After struggling to find some purpose in his life as a hero, Wade Wilson (Ryan Reynolds) retires as Deadpool, settling into a normal life as a car salesman, but also getting dumped by Vanessa (Morena Baccarin). He is brought in by the Time Variance Authority, or rather a rogue sector led by Paradox (Matthew Macfadyen), to join Earth-616 (in a meta sense, join the MCU) since Wade is told that his universe is on the verge of dying because the “anchor being” that keeps the universe in balance is dead, and that is the same Logan/Wolverine that died protecting his biological daughter Laura (Dafne Keen)and other mutant children. Wade goes through other universes until he finds a classic yellow and blue suit Wolverine to save his world, but Paradox says that this Wolverine (Hugh Jackman) is the worst since he let his own universe down.
Paradox sends Wade and Logan into the Void, where they come across old mutant villains and heroes from the Fox Marvel films. Wade and Logan encounter Johnny Storm before they are captured by mutants like Pyro, Toad, and Juggernaut. They work for Cassandra Nova, the psychotic twin sister of Charles Xavier who was banished to the Void because of her dangerous powers. She kills Johnny and prepares to leave Wade and Logan to be killed by Alioth, but they escape. The two are found by surviving heroes Elektra Natchios, Blade, and Gambit, who are led by Laura to try and fight Cassandra. Logan is reluctant to join, because in his universe, he wasn’t there to protect the other X-Men when they were attacked and murdered, leading him to go on a murderous rampage where innocent people got killed. After a talk with Laura, he joins the fight.
The heroes attack Cassandra’s base and use Juggernaut’s helmet to subdue her powers. After trying to convince her that they can save her brother’s universe, she opens a portal using one of Doctor Strange’s sling rings so they can return home. However, she learns from Pyro that Paradox is using the Time Ripper, to prune timelines faster, and since the TVA sent her to the Void, she kills Pyro and travels to Wade’s universe to use the Time Ripper and destroy every universe until all that is left is the Void.
Deadpool and Wolverine finally team up after the Deadpool Corps (an army of Deadpool variants) shows up to fight them until Wade’s buddy Peter shows up to save them since every Deadpool has a Peter. Paradox tells them that one of them has to redirect the Time Ripper’s energy but it would kill them. Wade and Logan use their bodies to do the job, which destroys the Time Ripper and blows Cassandra up. Paradox is arrested by Hunter B-15, and Wade learns his universe is being healed. He asks B-15 to help bring back the other heroes from the Void.
Wade invites Logan and Laura to be part of his universe, while he appears to reconnect with Vanessa.
