Xindi incident

The Xindi incident or Xindi crisis was a series of events lasting nearly a year, from March 2153 to February 2154, involving the Enterprise's attempt to save Earth from destruction by the Xindi. It was a major turning point in the Temporal Cold War, and the incident also helped pave the way for the creation of the Coalition of Planets, and later the United Federation of Planets.

Preemptive strike
In March of 2153, acting on false intelligence provided by the Sphere Builders, the Xindi launched a surprise attack on Earth. The Xindi, who had been without a homeworld since the 2030s, had been informed by their protectors that, in the 26th century, Humanity was going to destroy their new homeworld.

Because of this, the Xindi-Primate scientist, and Xindi Council member, Degra had been working for several years on a weapon capable of destroying Earth. 

It was the first prototype of the weapon, a small one-man vessel crewed by a Xindi-Reptilian soldier, that carried out the first attack on Earth. It utilized a powerful particle beam to carve a swath of destruction from Florida to Venezuela, killing seven million people. The vessel subsequently self-destructed; portions of this vessel were recovered by a Vulcan ship in Central Asia. 

As a result of this attack, Starfleet recalled Enterprise NX-01, which at the time was on a deep-space exploration mission. The tragedy on Earth was of a personal nature to one of Enterprise's crew; Commander Charles Tucker's sister, Elizabeth, was killed in the attack. 

On the way back to Earth, however, Enterprise was intercepted by a Suliban Cabal fleet. Suliban soldiers boarded Enterprise and seized Captain Jonathan Archer from the bridge, transporting him to see Silik, one of the leaders of the Cabal. Archer initially suspected Silik may have had something to do with the attack, but Silik took Archer to the temporal chamber to talk with his master from the future.

The Suliban benefactor told Archer that Earth had been attacked by the Xindi, operating on behalf of a new faction in the Temporal Cold War. He told Archer the reason for the attack: they had been told that Humanity was going to destroy the Xindi homeworld in the 26th century, and they wanted to stop this from happening. To do so, they were constructing a much larger weapon capable of destroying all of Earth in one stroke. He also gave Archer a set of coordinates, telling him the Xindi would be found there. Archer was extremely skeptical, but the mysterious figure told Archer to quantum-date the wreckage of the probe. After this, the Suliban returned Archer to his place on Enterprise.

Enterprise returned to Earth on April 24, 2153, where it was greeted by three Earth ships, including the starship Intrepid. , the captain of the Intrepid, hailed Enterprise and welcomed them home after their long journey. Once at Starfleet Command, Archer relayed the tale the Suliban benefactor had told him. Admiral Maxwell Forrest and Vulcan ambassador Soval were initially skeptical, but Archer proved at least part of the mysterious figure's story by showing that a portion of the probe had been built in 2573.

Soval remained unconvinced. He revealed to Archer that the coordinates he had been given were those of the Delphic Expanse, a dangerous region of space. Trying to stop Archer from proceeding with his mission, Soval showed the captain footage from the Vulcan starship Vaankara, whose crew had suffered severe psychosis while on a mission in the Expanse. Archer and Forrest were unswayed by Soval, however, and Forrest authorized Enterprise's new mission. 

Search for the Xindi weapon
In preparation for its new mission, Enterprise was heavily upgraded. A new weapon developed during the ship's journey of exploration, the photonic torpedo, was added to its arsenal. A new command center was installed, replacing a storage bay for conduit housings. This center possessed an advanced computer system for coordinating any information Enterprise might find on the Xindi. An upgrade to the universal translator was also installed. 

None of the senior staff opted to leave the crew, not even Doctor Phlox, a Denobulan, or Subcommander T'Pol, a Vulcan, despite the fact that this mission supposedly did not directly concern them. T'Pol, in fact, resigned her commission in order to accompany Enterprise, as the Vulcan High Command had ordered her to return to rather than accompany Enterprise into the Expanse. 

A significant addition to the crew was provided by General Casey at the request of Archer: a full contingent of Earth's most elite ground forces, the Military Assault Command Operations (MACO) group. Enterprise's contingent was commanded by Major Joss Hayes. Enterprise chief armory officer Lieutenant Malcolm Reed greatly resented the presence of the MACOs, believing that the need for this "extra muscle" reflected poorly on his security staff. 

It took Enterprise seven weeks at Warp 5 to travel from Earth to the Expanse (the ship arrived in August), and even then six more weeks passed while the ship began to fruitlessly comb the Expanse for any reference to the Xindi. The crew turned up only one lead: a freighter captain who had once taken a Xindi passenger to a trellium mining planet. During this time, Enterprise had its first encounter with the mysterious spatial anomalies that peppered the Expanse. 

Enterprise arrived at the trellium mine in September. Captain Archer bartered with the mine's foreman and was permitted to see the Xindi Kessick in exchange for a quantity of liquefied platinum. Kessick, however, did not match the genetic reconstruction of what the Xindi corpse – recovered from the probe – might have looked like, originally. Kessick was a Xindi-Primate, one of what he revealed to be five species of Xindi. Phlox determined that the different Xindi races shared over 99.5% percent of their functionally-important DNA, making them more similar to each other than Humans were to chimpanzees.

Kessick was killed while trying to help Archer and Tucker escape the mine (they were rescued by the MACOs), but with his dying words he managed to communicate the coordinates of the Xindi homeworld. Arriving at the coordinates, however, Enterprise found nothing more than a debris field; the planet had been destroyed approximately 120 years ago. With no further leads at that point, Enterprise set a course deeper into the Expanse. 

Enterprise next entered the Orassin distortion field, where it began to experience ever-increasing amounts of anomalies. After being incapacitated by one, Enterprise was boarded by Osaarian pirates, who raided the vessel for valuable supplies. Following the trail of the Osaarian ship, Enterprise discovered a massive cloaked sphere generating waves of gravimetric energy; it was this sphere that was responsible for all the anomalies nearby. Enterprise managed to recover its missing valuables from a cache inside the sphere. The ship's crew also managed to download a Xindi database from the Osaarians, who had originally acquired it from a Xindi-Arboreal ship they had pirated. 

Enterprise followed the trail of the ship in the database as far as the Loque'eque homeworld, but turned up no useful information. Shortly thereafter, Enterprise stopped at a deuterium station on Norellus, where Captain Archer spoke to a V'radian chemist named B'Rat Ud. Archer had learned from the Osaarians that the mineral trellium-D could be used for protection against the anomalies in the Expanse, and was interested in acquiring some for Enterprise. Archer arranged to rendezvous with B'Rat at his shop on the Xanthan homeworld in a few days. 

First encounters with the Xindi
Arriving at the Xanthan bazaar, Commander Tucker acquired the formula for synthesizing trellium-D from B'Rat in exchange for spices from Chef's galley. While Archer was at the bazaar, he was accosted by a dealer in sex-slaves named Zjod. Archer refused to buy any, but as he left, one of them ran after him, and Archer assisted in her escape. Archer offered to transport Rajiin to her home planet of Oran'taku, but she abused his hospitality, taking biometric scans of many of the crew using her telepathic abilities.

When Archer realized what she was doing, he had her locked in the brig, an action which precipitated Enterprise's first encounter with the Xindi. Two Xindi-Reptilian ships attacked Enterprise, and a strike team from one boarded the ship and recovered Rajiin despite a valiant defense by the MACOs. It turned out that Rajiin was a Xindi plant, compiling information so the Xindi could build a bioweapon as an alternate method of destroying Humanity. 

Enterprise continued deeper into the Expanse, still searching for a way to acquire trellium-D, as B'Rat Ud's directions had proved useless. The ship discovered a trellium asteroid field, and Commander Tucker and Ensign Travis Mayweather were successful in mining enough trellium to line the hull. However, the discovery of the Vulcan starship Seleya in the field showed that trellium causes Vulcans to undergo mental collapse; because of the threat to T'Pol, Archer elected not to line Enterprise's hull with trellium and had the material placed in a bio-hazard locker. Later on, however, the hull of Shuttlepod 1 was lined with trellium to enable it to take detailed scans of spheres. 

Following a tip from the telepath Tarquin, Enterprise arrived at a Xindi-Arboreal colony in October. This colony was home to a kemocite refining facility run by Gralik Durr; the kemocite mined here had been used in the probe and, in fact, Degra was shortly to visit the colony to pick up his final shipment. Archer explained the situation to Gralik, who was shocked that his people would try to destroy a planet after what had happened to Xindus; he told Archer of the sixth Xindi species, the Avians. Gralik sabotaged the kemocite shipment, and T'Pol and Hoshi Sato altered a canister's radiolytic signature to allow Enterprise to track it. 

In November of 2153 (after Enterprise had encounters with a lost Human tribe and a polaric field), Captain Archer was once again contacted by, an operative in the Temporal Cold War who had assisted Enterprise on several previous occasions. Daniels informed Archer that the Xindi attack on Earth was the result of a temporal incursion whose effects had not yet reached his own time, so he would be unable to assist in the search for the weapon. 

Daniels did, however, bring word that three Xindi were present in the year 2004 on Earth, where they had been operating for two months. Daniels sent Archer and T'Pol backwards in time to deal with the threat. Archer and T'Pol discovered that Xindi-Reptilian scientists were assembling a bioweapon to wipe out Humanity in the past; later information would show that after the Rajiin incident the Xindi Council had banned further research into the bioweapon and that the Sphere Builders had taken the biologist Damron and his team into the past to covertly complete their work. Archer and T'Pol successfully stopped the bioweapon from being deployed and returned to 2153. 

In December, Enterprise finally managed to reacquire the radiolytic signature of Gralik's kemocite shipment. Degra was testing a second prototype in the Calindra system, but as Enterprise approached the location, it was nearly disabled by a dense anomaly field. Enterprise was rescued by the Kumari, an Andorian vessel under the command of Shran. Shran pledged help in finding the weapon; when the Andorian Imperial Guard had heard of the attack on Earth, the Kumari had been dispatched to assist Enterprise and tracked the vessel through the Expanse with its faster warp drive. 

The Kumari and Enterprise (after witnessing a failed test of the weapon; the failure no doubt caused by the sabotaged kemocite) were able to work together to steal the prototype weapon. The Andorians attempted to make off with it for themselves for use as a deterrent in their conflict with the Vulcans, but Captain Archer triggered its self-destruct rather than let the Andorians keep it. The Kumari subsequently returned to Andoria, but Enterprise remained in the system to investigate further. Degra's shuttle was detected in the system, examining the effects of the test, and he and his assistants were captured by Enterprise personnel. 

Doctor Phlox wiped Degra's memories and through an elaborate subterfuge, Archer was able to convince Degra that the two had spent years together in a Xindi-Insectoid prison after the destruction of Earth. Archer managed to get Degra to reveal the coordinates of the Azati Prime system, where the weapon was being built. Degra and his assistants were placed back on their ship, their memories wiped again, and none of them the wiser that anything had ever happened. 

Showdown with the Xindi
Enterprise's journey to Azati Prime took some time, as the Earth vessel was not equipped with the subspace vortices Xindi vessels used to move quickly across the Expanse. During this journey, Enterprise discovered a mysterious alien adrift in a small pod in a transdimensional disturbance; the crew quickly discovered he was somehow related to the builders of the spheres. The alien was dying as he could not survive in the conditions of our universe. 

Back in November, Enterprise had encountered a species called the Triannons who worshiped the Makers of the spheres. They claimed that the Makers were using the spheres and the anomalies they generated to reshape the Expanse; given the discovery of this "test subject," it appeared that the Triannons had been partially right. The alien attempted to sabotage Enterprise before disintegrating entirely; before he did, he revealed a link between the Xindi and the Sphere Builders, claiming his people would triumph when Earth was destroyed. 

On course to Azati Prime, Enterprise negotiated another transdimensional disturbance in January; afterward, it came upon the crash site of a Xindi-Insectoid ship. The crew recovered a shuttle from the wreckage, which was brought into Enterprise's launch bay. 

In February of 2154, Enterprise at long last slipped into the outskirts of the Azati Prime system, behind a planetoid. Using the stolen Insectoid shuttle, Tucker and Mayweather were able to determine that the weapon was being built underwater on Azati Prime; they also learned that it was undergoing the final stages of construction. Captain Archer concocted a plan to destroy it: he would take the Insectoid shuttle in, loaded with photonic torpedoes, and blow it up.

Before he could do this, however, Daniels returned, whisking Archer away to the Battle of Procyon V aboard the USS Enterprise (NCC-1701-J) in the 26th century. He revealed that at this time the Sphere Builders were making a push to invade the Milky Way Galaxy, but at this battle the forces of the United Federation of Planets defeated them, pushing them back into their transdimensional realm. With their ability to look into the future, the Sphere Builders foresaw that these events would occur, and manipulated the Xindi into their plan to destroy Earth, so that the Federation would never be founded, and the Sphere Builders would face no opposition in the future.

Daniels tried to persuade Archer not to go forward with his plan, but rather pursue a diplomatic solution, as Archer was an integral component in the founding of the Federation, and undertaking a suicide attempt would jeopardize the future. Archer was not persuaded, however. He went ahead with his plan anyway and was captured by security forces under the command of Commander Dolim. Archer, using information he had acquired during his subterfuge at Calindra, secured an audience with Degra and managed to communicate Daniels' story. 

Meanwhile, Enterprise came under heavy attack by Xindi forces, causing massive damage to the vessel. Fortunately, Degra managed to force the Xindi Council to order Dolim to call off the attack, and he secured the return of Archer to his ship, arranging a secret rendezvous in three day's time so Archer could show him evidence that the Xindi were being manipulated by the Sphere Builders. 

Unfortunately, the ship's primary warp coil had been damaged during the attack, rendering the ship unable to travel at warp speeds, meaning it would never be able to reach the rendezvous in time. Enterprise was assisted in its repair efforts by an Illyrian vessel that had been disabled by an anomaly field; Enterprise helped the Illyrians in turn. They were unwilling, however, to part with their warp coil because not having it would mean a three-year journey home. Believing the rendezvous with Degra necessary to the survival of Humanity, Archer and the MACOs boarded the Illyrian craft and stole their warp coil. In return, Enterprise transported food and trellium-D to the Illyrian craft. 

Enterprise rendezvoused with Degra as well as Arboreal councilor Jannar behind the cloaking barrier of one of the spheres, where Archer showed them evidence of the Guardians' treachery: the bioweapon recovered from 2004, the bodies of Damron and his associates, scans of the Sphere Builder test subject, the ship's database on the spheres, and more. Degra thought that Archer deserved a chance to bring his case before the Council and arranged a rendezvous on the other side of a subspace corridor in the Kovaalan nebula. Degra went so far as to destroy a Reptilian vessel trying to bring him back to the Council. 

Enterprise traversed the corridor, but not without difficulty; the ship battled the Kovaalans and very nearly traveled to 2037, but eventually made it to the rendezvous early. Degra brought Archer before the Xindi Council, where he presented his case. The Arboreals and Primates were swayed, but the Reptilians and the Insectoids were so outraged by the presence of Archer that they walked out. Archer still needed the support of the Aquatics to obtain a delay on the weapon launch; he obtained it when he persuaded Councilor Kiaphet Amman'sor to vote for it with a biometric hologram of the Sphere Builder test subject. However, an enraged Dolim murdered Degra and had the weapon stolen, operating on instructions from a Sphere Builder who promised that the Reptilians would be at the head of the Xindi in the future if they acted against Earth immediately. Dolim was assisted by the Insectoids. 

The weapon required launch codes from three of the five species to be armed; as he possessed only two of them, Dolim kidnapped Enterprise linguist Hoshi Sato and used Xindi neural parasites to force her to decrypt the third code. As the weapon could not arm while in flight, and this delay allowed Archer to convene an alliance of Primates, Arboreals, and Aquatics to stop the weapon. Amman'sor promised her forces' support only when Archer promised Enterprise would try to disable the sphere network. 

The combined assault team managed to destroy most of the weapon's defensive forces, but thanks to Sphere Builder interference, the weapon was able to enter a vortex bound for Earth, armed and ready, accompanied by both a Reptilian and an Insectoid vessel. Hoshi Sato was eventually rescued, though Major Hayes was killed in the operation. However, on their way to Earth, Dolim ordered his ship to destroy the Insectoids' ship after the Insectoid councilor said he was considering Archer's evidence. 

The only ship left that was capable of catching up to the weapon in the vortex was Degra's. So Archer, Reed, Sato, Jannar, the other Xindi-Primate councilor, and a MACO strike team boarded the ship in hot pursuit. They caught up to the weapon near Earth, though not before the Xindi destroyed the Yosemite 3 research station. Degra's lightly-armed ship was no match for the Reptilian vessel guarding the weapon, and they could not get close enough to beam aboard. Luckily, Shran and the Kumari showed up at that moment to run interference for Degra's vessel; the Andorian ship had tracked them through the vortex. While the Kumari distracted Dolim, Archer and his team transported on board the weapon. The MACOs killed all the Reptilians on board as Archer started the inversion sequence that would deactivate the power to the weapon. Meanwhile, Dolim realized what the Kumari was doing and ordered his ship to return to the weapon. 

After killing the Reptilian squad aboard the weapon, Archer's strike team transported back to Degra's shuttle, as Archer successfully overloaded the weapon's reactor. However, a determined Commander Dolim transported to the weapon to reverse the damage done just before Archer was slated to beam off himself. The two then fought each other in hand-to-hand combat as the weapon began to explode around them. Meanwhile, the Kumari destroyed Dolim's vessel, leaving him with no way to get off. As the weapon continued to disintegrate, Archer placed an explosive charge on Dolim's back and blew him up. However, Archer was not able to transport off in time as the weapon completely exploded in Earth orbit. Degra's vessel returned to the Expanse to rendezvous with Enterprise.

Aftermath
Meanwhile, Enterprise had been making good on Archer's promise to Amman'sor by using a deflector beam to damage one of the spheres' interspatial manifolds that linked each sphere to one another. Without energy, the spheres collapsed in upon themselves, and the Expanse started to re-align with normal space.

Enterprise met up with Degra's shuttle, and an Aquatic carrier returned Enterprise to Earth. However, as Enterprise approached Earth, it received no return signals from Starfleet. A shuttlepod sent down to San Francisco was attacked by P-51 Mustangs, a World War II fighter aircraft. Meanwhile, Captain Archer awoke in a Nazi field hospital in the presence of a Na'kuhl SS officer. 

It became apparent that Enterprise was in fact in the year 1944 in an alternate timeline where the Nazis were able to the United States of America's eastern seaboard. The Temporal Cold War had escalated to an all out conflict and the 22nd Century that they knew of no longer existed. Enterprise had been brought back to the past by Daniels to defeat Vosk and members of his faction in the temporal war. Once Vosk was defeated the timeline subsequently returned to normal. Daniels sent the ship back to 2154, where a large armada of Earth ships had assembled and escorted Enterprise home. 

Enterprise received a hero's welcome at Earth, a thought that caused Captain Archer some distress, as twenty-seven crew members had died and he himself had committed some morally questionable acts. Despite what reservations he may have had, high schools were being named after him, and his crew was lauded with praise and admiration for what they had done. 

Unfortunately, the conflict had also caused increased xenophobia amongst Humans towards non-Humans, resulting in support for extremist group Terra Prime. The group attempted to derail negotiations for a Coalition of Planets by attempting to force all non-Humans to leave the Sol system, but failed due to Enterprise's intervention. Ironically, it may have had the opposite effect, as the incident made the resolve stronger and eventually resulted in the creation of the United Federation of Planets.