In 2018, Wade Wilson, portrayed by Ryan Reynolds, utilizes Cable's time-traveling gadget to venture from his original timeline, Earth-10005, to Earth-616, often referred to as the "Sacred Timeline." There, he seeks out Happy Hogan to join the Avengers, but is ultimately turned down. Fast forward six years later, and Wade has traded in his life as the notorious masked mercenary known as Deadpool to operate a used car dealership after a heartbreaking split from his girlfriend, Vanessa Carlysle (Morena Baccarin).
During his birthday celebration, the Time Variance Authority (TVA) intervenes, taking Wade before Mr. Paradox (Matthew Macfadyen), who presents him with an opportunity on Earth-616. However, Paradox reveals a shocking truth: Wade's timeline is crumbling following the demise of James "Logan" Howlett (also known as Wolverine, played by Hugh Jackman), who acts as the "anchor being" for that timeline. In a bold move, Wade pilfers Paradox's TemPad, determined to traverse the multiverse in search of a variant of Logan to rescue his timeline.
Wade encounters an array of Logan variants but eventually brings one back to the TVA, only to discover this particular variant had obliterated his own universe. They are both abruptly pruned into the Void by Paradox. A conflict erupts between Wade and Logan, but they, along with Johnny Storm (Chris Evans), are soon captured by Cassandra Nova (Emma Corrin), who is revealed to be the twin sibling of the famed X-Men leader, Charles Xavier. Upon reaching Nova's lair, she exhibits her mind-manipulating abilities and discloses her arrangement with the TVA to remain in the Void as a gang leader. In a brutal twist, she eliminates Johnny while attempting to toy with Wade’s emotions, questioning his sense of worth before the ominous entity, Alioth, appears. Fortunately, Wade and Logan manage to escape before being consumed.
In the aftermath, Logan and Wade meet a variant of Wade known as Nicepool, who grants them a vehicle to facilitate their journey to the Void's borderlands and join forces with the resistance against Nova's tyranny. However, Logan reproaches Wade for concealing his uncertainty in fixing Logan's timeline. Upon their arrival at the borderlands, they encounter Elektra Natchios (Jennifer Garner), Blade (Wesley Snipes), Remy LeBeau (known as Gambit, played by Channing Tatum), and X-23 (Dafne Keen), collectively identified by Wade as "the Others." Although Logan initially hesitates to collaborate, a significant conversation with X-23 about his failures with the X-Men ultimately persuades him to join the fight.
As they confront Nova, who has confined Logan's mental faculties, Wade cleverly places Juggernaut's helmet upon her to inhibit her powers. Pyro (Aaron Stanford) surfaces, unveiling himself as Paradox’s sleeper agent tasked with eliminating Nova. Encouraged by Logan, Wade ultimately opts to remove the helmet, allowing Nova to recuperate in return for a portal to transport them back to Wade's timeline via a sling ring from a variant of Doctor Strange.
Upon their highly anticipated arrival on Earth-10005, Wade and Logan discover that Paradox has devised the Time Ripper, a chilling contraption meant to annihilate timelines, including Wade's, all without his superior's endorsement. In a dramatic turn of events, Nova, having learned of Paradox's betrayal, arrives through another portal and seizes him. An intense skirmish ensues as Wade and Logan take on the Deadpool Corps, an army of Deadpool variants pouring through the portal. Nova, now powered by her fury, commandeers the Time Ripper to exact vengeance by attempting to erase all timelines. Paradox informs Wade and Logan that they can disrupt the Time Ripper's energy flow at the cost of their own lives. Choosing to sacrifice themselves, they successfully vanquish Nova and obliterate the Time Ripper, miraculously surviving the ordeal. Soon after, Hunter B-15 (Wunmi Mosaku) apprehends Paradox.
Wade requests that the Others return to their timelines, while Logan is granted permission to remain with Wade on a healed timeline. As Logan longs for alterations to his history, B-15 reminds him that his past is what sustains him as the vital anchor for Wade's timeline, negating further changes. Coming to terms with this revelation, Logan opts for a life of tranquility. Before taking his leave, Wade invites Logan and Laura to meet his friends, leading to a heartfelt reconciliation with Vanessa, inspired by Logan’s encouragement.
