After learning the Dominators’ plan for the world, the Legends must work together with The Flash, Supergirl and Green Arrow to kill them once and for all. Meanwhile, Stein figures out, with the help of others, how the team can terminate the Dominators, but is distracted by the aberration he realizes he created in 1987. The crossover starts on Supergirl S02E08 Medusa (I), The Flash S03E08 Invasion! (II) and Arrow S05E08 Invasion! (III).

Barry and Iris's wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. All of the superheroes band together with help from their super friends like Citizen Cold, The Ray, Felicity Smoak, Iris West and Alex Danvers to take on their most formidable villains yet. Earth's mightiest heroes - Green Arrow, Supergirl, The Flash and White Canary - lead their teams into battle to save the world. The crossover starts on Supergirl S03E08 Crisis on Earth-X (I), Arrow S06E08 Crisis on Earth-X (II) and The Flash S04E08 Crisis on Earth-X (III).

After the team returns from a mission, Zari finds herself trapped in a time loop that results in the Waverider blowing up over and over again. Zari soon begins to suspect that the answer to stop what is happening might lie hidden among her fellow shipmates' secrets. But in investigating them she starts to understand her place on the team.

When a massive timequake rocks the ship while the legends are preparing for their next destination, they must break a cardinal rule of time travel.

With Astra, Spooner and a now-human Gideon trying to save the Legends, Gideon becomes overwhelmed by her new human choices sending her into a catatonic state. Astra and Spooner combine their powers to enter Gideon's mindscape and discover that a virus is trying to erase all of Gideon's memories. Acting fast, they devise a plan to defeat the virus before it's too late. Meanwhile, the Legends are about to go up against a powerful new foe.

The Legion of Doom rewrites history after obtaining the Spear of Destiny, potentially changing the Legends forever.

After Constantine breaks the cardinal Legend rule—you can’t change the past—he, along with Charlie and Zari try to deal with the ramifications without telling the rest of the Legends. Even though Zari encourages them to just fix the problem, Constantine and Charlie are determined to find another way, but only continue to make things worse.

Ray plans a date night for him and Nora, but all goes awry when an Encore shows up making the team think on their feet and create a lie to keep the Encore at bay. While trying to fool the Encore, Ava learns what Sara was really doing while she was away and confronts her. Charlie and Constantine make a deal to work together, which will benefit both of them. Meanwhile, Rory is upset when he gets negative comments about his book, so Zari helps track down who the critic is, and Rory gets more than he bargained for.

After Charlie does the one thing that goes against her nature when it comes to her sisters, she tries to protect the Legends by scattering them in different television shows. Of course, in true Legends style some can’t just be blissfully ignorant and happy but figure out a way to end up messing with the system.

Being in the vicinity of the Time Masters leaves Rip and Rory incredibly disturbed for very different reasons. Meanwhile, Sara takes over the Waverider, Kendra is reunited with Carter and Snart decides he might be a hero after all.

The Legends are determined to find and rescue Rip, but first must focus on locating the Spear of Destiny. Stein thinks he has the perfect person to help but knows involving her will be risky. Meanwhile, Malcom Merlyn and Damien Darhk realize that Thawne is pitting them against each other.

The Legends learn that Ray Palmer will die because they broke time, causing them to race back to 1988 to try and save his life. When they arrive, they are surprised to learn that young Ray Palmer has befriended a time-displaced baby Dominator putting him in harm's way with the government and the Dominator's mother. New to the ship and missions, Zari must find her place and learn to trust the team. Meanwhile, Stein begins working on a secret project on the ship which makes Rory and Jax suspicious.

The Legends plan to vanquish Mallus by using the totems doesn't go as planned, forcing Rip to improvise. The team finds itself regrouping in the Wild West where they run into their old pal Jonah Hex. Sara leaves Ray in charge of watching Damien Darhk, while she comes up with a new plan. Meanwhile, Amaya is determined to find a way to use the totems to destroy Mallus.

When a malfunction sends the Waverider crashing into 2046 Star City, our heroes face a startling version of their own future where they never stop Savage and never return home. The city is in ruins and overrun by criminals, which thrills Rory. Sara is despondent over the destruction of her home and stunned when she learns what happened to her old friend, Oliver Queen.

After the numerous sacrifices the team has made since the beginning of this ride, Rip decides that it’s time they each decide their own destiny and returns them to Central City a few months after they first left. Returned to their normal lives, each team member must individually decide if they are willing to sacrifice everything in order to save the world. Meanwhile, Sara visits with her father who delivers some heartbreaking news about her sister.

With the timeline barely stable, the Legends must tackle two anachronisms at the same time to try and keep Mallus at bay. Sara and Rip team up to stop Grodd from going after a particular target leaving Nate and Wally to stop Amaya from changing her future. Meanwhile, the Legends think they have found a way to destroy Mallus, but they will have to create an uneasy alliance with one of their enemies.

“Worlds lived, worlds died. Nothing will ever be the same.” The crossover starts on Supergirl S05E09 Crisis on Infinite Earths: Part One (I), Batwoman S01E09 Crisis on Infinite Earths: Part Two (II), The Flash S06E09 Crisis on Infinite Earths: Part Three (III) and Arrow S08E08 Crisis on Infinite Earths: Part Four (IV)

When the Legends discover a new Encore, Sara, Rory and Ava end up crashing a high school reunion to attempt to stop a serial killer from finishing unfinished business. The Legends devise a plan to send Nate, Ray, Nora, Behrad and their hostage Zari, back in time to try and intervene in order to try to save everyone including them. Meanwhile, Constantine is annoyed that Charlie has been squatting in his old home, but it might be the blessing in disguise they were not looking for.

With Ava a wreck, the Legends make a last-ditch effort to keep Sara from being abducted in the first place, even knowing that it will alter the timeline. Sara grapples with a discovery about herself and is shocked when Rory finds her on the mystery planet. Meanwhile, Spooner envisions what her life would be like if she hadn't joined the Legends.

With the Legends tired of being chased by an evil A.I. and her robo-soliders, Sara decides to create an aberration that will allow the team to take back the Evil Waverider. However, they find themselves in a bar for time-travelers and quickly learn that this "fixed point" is popular with time-travelers, leaving Sara questioning her odds at winning. With Behrad and Astra growing closer, Zari and Spooner are forced to awkwardly interact with each other as the rest of the Legends are paired up on the mission. Meanwhile, Ava hears Gwyn's plan to save his boyfriend, and is forced to remind him of the consequences in he succeeds.

Dr. Nate Heywood, an unconventional historian, makes a shocking discovery. Nate then seeks out Oliver Queen for help to find the scattered Legends. Once reunited, they try to protect Albert Einstein from being kidnapped before the Nazis destroy New York City with a nuclear bomb. Meanwhile, Ray notices that Sara has a mission of her own, which leads them both to face her nemesis, Damien Darhk.

The Legends must devise a plan to retrieve the last remaining fragments of the Spear of Destiny from the Legion of Doom. They find themselves in France at the height of World War I faced with the knowledge that they must destroy the mystical object. They enlist the help of a soldier by the name of John Ronald Reuel Tolkien and find that the Spear is leading them into the heart of the war. Meanwhile, the team must all resist the temptation of the Spear, and the return of a former teammate.

Rattled by recent events, the Legends dive into work which finds them investigating an Anachronism in a Viking settlement in the New World. The Legends realize that the Norsemen are worshiping an artifact as their god and are surprised by the artifact's origin. For the first time, Sara is worried that they might need back up when Damien Darhk shows up. Meanwhile, Jax finds a loophole that could potentially change history, but it is a risk he is willing to take.

After Sara's encounter with Mallus, the Legends are paid a visit by John Constantine, a demonologist detective. The Legends agree to accompany him to a present-day psychiatric hospital and they are surprised to discover who Constantine is trying to help. During the exorcism, Sara, Leo and Constantine go missing, leaving Ray and Zari to try to take care of Constantine's client. Meanwhile, Amaya and Nate once again come face to face with Kuasa.

When Mallus' power over Sara resurfaces, she unwittingly becomes the bearer of one of the Totems. Rory must conquer his dark side in order to wield his own Totem power to help save the crew. Meanwhile, Agent Sharpe notices that something is wrong and recruits someone unorthodox to help.