Jones, whose own Destiny Force is determined to be responsible for his deteriorating health, is brought by the Avengers before the Kree Supreme Intelligence for possible help. As the Intelligence determines what to do, Immortus summons his minion Tempus to dispatch of Jones, thus ending humanity’s threat to future timelines. Unfortunately for Immortus, his “other self” Kang materializes and thwarts Tempus’ efforts. As Immortus and Kang poise to do major battle, the Intelligence’s ally, Libra, aids Jones in reactivating his dormant Destiny Force to assist Kang. Rick summons from various points in Avengers history Captain America (from shortly after his battle with the Secret Empire), Hawkeye (from right after the Kree-Skrull War), Yellowjacket (from shortly after the Vision joined the Avengers), the Wasp and Giant Man (from the-then present), and Songbird and Captain Marvel, (both from the not-too-distant future).
It’s revealed that Immortus desires to control all timelines via a device called the Forever Crystal (formerly the Heart of Forever). He actually comes to acquire the device, but Jones and his team of Avengers take sanctuary outside of the time stream for protection. Nevertheless, Immortus begins to use the Forever Crystal to go about altering and/or destroying “dangerous” timelines. In one of these timelines, the world of Killraven where an alien race used Mars as a launching pad for an invasion of conquest, he makes it so humanity cannot launch into space to pursue their former conquerors. He does this by manipulating several beings’ need for Earth’s remaining supply of vibranium – Jocasta’s for her newborn baby, and Mourning Prey’s for her offspring – but necessary for Earth’s spacecrafts’ fuel. In another, an Earth where the Avengers were formed in the 1950s, then-Vice President Richard Nixon is discovered to be a Skrull. Immortus decides to outright destroy this timeline, fearing that a newly xenophobic humanity will bring only conflict to the galaxy.
Many revelations take place during the course of the war, including that Kang was not actually responsible for the Crossing (it was Immortus), that there are many, not just one Space Phantom[s], and that the Vision’s origin encompassed both versions (that of Ultron and Prof. Phineas Horton) witnessed in the past.Immortus eventually captures the assembled Avengers and brings them before the Time Keepers so as to hear their explanation of what they must do. Here, they state to the heroes that humanity is "the most dangerous beast in the universe." They plan to destroy 42% of all timelines where humanity travels to the stars and becomes a (possible) threat. In effect, humanity will be "imprisoned" across all timelines as a result of the Time Keepers actions. Using their individual Destiny Forces to escape their imprisonment, the Avengers – along with a newly arrived Kang, Rick Jones and Supreme Intelligence - temporarily stop the Time Keepers. The Keepers escape to "the end of time" but are pursued by Jones and his compatriots. To stall their attackers while they prepare for the destruction of the necessary timelines, the Time Keepers summon from across the multiverse countless "Avengers who turned bad." But Rick Jones, together with his future counterpart, summon myriad "good Avengers" to fight them. Rick ends the fight – and hence the war – by throwing himself into the Time Keepers’ chrono-cannon. Capt. America seemingly destroys the Forever Crystal, but Immortus informs the assemblage that destroying the crystal "is not permanent." Indeed, immediately after the war’s conclusion, the Supreme Intelligence comes into possession of the crystal, which he would later use to alter his own Kree race.