Deadpool, the wisecracking mercenary Wade Wilson, travels to the Sacred Timeline in 2018 hoping to turn his life around and finally become a genuine hero. Believing that joining the Avengers will give his life meaning, he meets with Happy Hogan to apply for membership. Happy is unimpressed, explaining that people become Avengers because others need them, not because they are searching for purpose or recognition. Deeply disappointed by the rejection, Wade abandons the Deadpool persona and attempts to live a normal life by taking a job as a car salesman at Drive Max. His relationship with Vanessa Carlysle also comes to an end, leaving him emotionally adrift and questioning his future. Six years later, while celebrating his birthday with Blind Al, Peter, Dopinder, and his other friends, Wade’s life takes another unexpected turn when agents of the Time Variance Authority suddenly appear and arrest him.

At TVA headquarters, Wade is brought before Mr. Paradox, a TVA official who offers him the opportunity to leave his universe behind and take his place on the Sacred Timeline, where he could finally become an Avenger. Overjoyed by what he believes is the opportunity of a lifetime, Wade eagerly embraces the offer and once again dons the Deadpool suit. His excitement is short-lived, however, when Paradox reveals that Wade’s home reality is dying because it has lost its “Anchor Being,” Wolverine, whose heroic sacrifice years earlier had preserved the stability of that universe. Rather than allowing events to unfold naturally, Paradox secretly intends to erase Wade’s timeline far sooner than scheduled by activating a powerful device known as the Time Ripper, all without the authorization of the TVA’s new leadership.

Refusing to abandon his friends and home, Deadpool steals a TemPad and embarks on a frantic journey across the Multiverse in search of another Wolverine who might replace the fallen hero. His quest begins at Wolverine’s grave, where he discovers that Logan is truly dead. After battling TVA Minutemen sent to stop him, Wade visits countless alternate realities, encountering a bizarre assortment of Wolverine variants—some savage, some ridiculous, and others completely unsuitable. Eventually, he discovers a bitter, alcoholic Logan drinking alone in a Canadian bar. This broken Wolverine dismisses Wade’s plea for help, but after drinking himself unconscious, Deadpool drags him back to the TVA. Paradox ridicules Wade’s plan, explaining that an Anchor Being cannot simply be replaced and revealing that this particular Logan is regarded as the most disgraced Wolverine variant in the Multiverse.

When Deadpool uncovers evidence that Paradox is acting outside the authority of the TVA, both he and Wolverine are immediately pruned and exiled to the Void. Furious at being manipulated into Wade’s scheme, Wolverine attacks him, resulting in a lengthy and brutal fight. Wade eventually convinces Logan that returning to the TVA might allow him to repair the terrible mistakes that destroyed his own world. Their uneasy alliance continues as they encounter Johnny Storm, whom Deadpool hilariously mistakes for Captain America, before crossing paths with Sabretooth and his gang of scavengers. During the ensuing battle, Pyro strips Johnny of his powers while Wolverine swiftly kills Sabretooth. Nevertheless, Pyro and Toad overpower the heroes and transport them to Cassandra Nova, the banished twin sister of Charles Xavier, who rules the Void from within the colossal remains of Ant-Man.

Cassandra Nova welcomes Deadpool and Wolverine with unsettling amusement. During their trip to her fortress, Deadpool jokingly claims that Johnny repeatedly insulted Nova behind her back. Although Johnny desperately protests his innocence, Nova mercilessly skins him alive using her terrifying telekinetic abilities. She then invades Deadpool’s mind, exploiting his memories of Vanessa and convincing him that he will always be a failure who will never matter. She also mentally overwhelms Wolverine before effortlessly defeating both heroes and abandoning them to be consumed by the monstrous Alioth. Against impossible odds, the pair narrowly escape certain death and decide to search for a mysterious Resistance that Johnny mentioned before his death.

On their journey, Deadpool and Wolverine meet Dogpool and the relentlessly cheerful Nicepool, who generously provides them with transportation and directions to the Resistance’s headquarters. During the drive, Wade accidentally admits that he has no proof the TVA can restore Wolverine’s reality and has been relying entirely on hope. Feeling betrayed yet again, Wolverine attacks Deadpool, and the two engage in another savage fight that continues until they collapse from exhaustion. Their abandoned vehicle is eventually recovered and delivered to the Resistance’s hidden base.

The Resistance is led by X-23 and includes alternate versions of Elektra, Blade, and Gambit, all of whom have been stranded in the Void by the TVA. Deadpool persuades them to unite against Cassandra Nova while conveniently omitting his role in Johnny Storm’s demise. Wolverine initially dismisses the mission as hopeless, believing himself beyond redemption, until X-23 privately confronts him. Logan finally admits that in his universe he abandoned the X-Men during a moment of crisis, allowing anti-mutant vigilantes to slaughter his teammates. Wracked with guilt ever since, he continues wearing his X-Men uniform as a reminder of his greatest failure. X-23 assures him that despite his mistakes, he remains the hero she has always believed him to be. At the same time, Pyro secretly strikes a bargain with Paradox, who concludes that Cassandra Nova has become too dangerous to control and orders her assassination.

Inspired by X-23’s faith in him, Wolverine joins the Resistance as they launch an assault on Cassandra Nova’s fortress. Their plan is to obtain Juggernaut’s helmet, the only object capable of neutralizing Nova’s overwhelming psychic abilities. Nova quickly incapacitates the attackers and enters Wolverine’s mind, tempting him to surrender to his rage and erase the guilt that has haunted him for years. Logan refuses, choosing to confront his past rather than escape it. Using Juggernaut’s helmet provided by X-23, Deadpool suppresses Nova’s powers and demands that she release everyone trapped within the Void. Before she can respond, Pyro suddenly shoots her. Refusing to let her die, Wolverine insists that Charles Xavier would never condone such an act of vengeance. Deadpool removes the helmet, allowing Nova to recover. In gratitude, she opens an interdimensional portal with a Sling Ring enhanced by the Reality and Time Stones, enabling Deadpool and Wolverine to escape moments before Alioth destroys the fortress. Nova then forces Pyro to confess that Paradox ordered her assassination before killing him herself.

Returning to Earth-10005, Deadpool and Wolverine discover that Paradox has nearly completed the Time Ripper. Cassandra Nova soon arrives, seizes control of the machine, and reveals her true ambition—to erase the entire Multiverse and transform every timeline into the endless Void she has come to love. She captures Paradox and unleashes the Deadpool Corps to stop the heroes. Deadpool and Wolverine battle an army of alternate Deadpool variants whose regenerative abilities make them almost impossible to defeat. The seemingly endless conflict finally comes to an unexpected end when Peter arrives, instantly earning the affection of every Deadpool variant and peacefully ending the battle.

Paradox explains that the only way to destroy the Time Ripper is to overload its matter and antimatter chambers, an act almost certain to kill whoever attempts it. Wolverine volunteers, believing he has nothing left to lose, but Deadpool locks him outside the chamber and prepares to sacrifice himself instead. Refusing to allow Wade to die alone, Wolverine breaks into the chamber and shares the overwhelming energy released by the machine. Working together, the two heroes overload the Time Ripper, destroying both the device and Cassandra Nova while preventing the complete collapse of the Multiverse. Their willingness to sacrifice themselves ultimately proves both men have become the heroes they always hoped to be.

Following the battle, B-15 and the TVA arrive to investigate the aftermath. Paradox is arrested for his unauthorized actions, while everyone initially assumes that Deadpool and Wolverine perished in the explosion. Instead, the pair miraculously survive by sharing the tremendous energy released by the Time Ripper. Wade asks B-15 to protect the Resistance members stranded in the Void and restore Wolverine’s home reality if possible. Although she explains that Logan’s tragic past cannot be erased because it ultimately led to the salvation of the Multiverse, she promises to do what she can to help their allies.

With peace finally restored, Wade and Logan celebrate by sharing shawarma before returning home with Dogpool. Wade takes Wolverine and Dogpool to meet Blind Al and later invites all of his friends—including X-23—to his apartment for a celebration. Encouraged by Logan, Wade decides to rekindle his romance with Vanessa and finally begins looking toward a brighter future. In a humorous post-credits scene, Deadpool returns to the TVA and proudly plays security footage proving that Johnny Storm really did insult Cassandra Nova, hilariously vindicating his outrageous story once and for all.