WARNING: The Following Article Contains Spoilers for Legends of Tomorrow's Season 4 finale, “Hey, World!”
Last season, the titular characters of the CW's off the wall superhero series Legends of Tomorrow saved all of time and space from the apocalypse by creating a giant supernatural avatar based on the cuddle happy kids toy, Beebo. So the question on many fans minds going into the Season 4 finale was, “How are they going to top that?” The answer was by staging a spectacle that combined the series' wildly imaginative and zany antics with heartfelt sentiment, humor and (because, why not) a musical review.
Of course, along the way some tragedy does strike the team, resulting in a massive status quo shift of a cliffhanger. Not only do the episode's final moments see one team member replaced by a new face, Season 5's overarching threat is revealed, one that leans heavily into the series' predilection for introducing real world people as major players in the Legends' adventures.
Throughout the second half of Season 4, the demon overlord Neron (dubbed NeRay because of him possessing the physical form of Ray Palmer) sought to use a massive outbreak of fear to open up a portal and bring the forces of Hell to Earth. NeRay and his significant other, former Fairy Godmother Tabitha, have orchestrated a series of incidents that painted magical creatures in a horrific light.
As a result, the Legends needed a plan that would change people's opinions about magical creatures on a large scale. Fortunately, the literal foundations for that plan were laid in a previous episode when Nate Heywood learned his deceased father had been writing the magical creatures-themed book he'd dreamt of as a kid, Heyworld. Thus, the finale used the mystical diary from the season's fifth episode, “Tagumo Attacks,” to finish bringing the park to life.
While the Legends were building Heyworld, Nora Darhk and John Constantine reunited in Hell and launched a plan with the now grown up Astra Logue, (the little girl John inadvertently condemned to hell in NBC's Constantine series) to steal Ray Palmer's soul from a bank that trades them as currency.
In a surprise twist, their heist attempt brought them face to face with the Legends oldest foe, Vandal Savage (Caspar Crump). Savage had been sent to torture Ray's, but the two got to talking, and Palmer won the former world conqueror over with his good nature. So, when Nora and Constantine find them, Savage is in a garrulous mood and offers up a concise and funny summary of Legend'slackluster first season. Constantine also learns from Ray that the key portion of his bargain with Neron was that by giving his soul, his best friend, Nate, would go unharmed by the demon.
During the episode's massive final fight, involving a talent show held by the world's mythical creatures (really), Tabitha is eaten by a dragon and NeRay attempts to use the fear he generated to open a portal to Hell. Constantine confronts NeRay and is seemingly killed by the demon. However, Constantine used his magic to make Nate look like the magician, and when Nate's dead body is revealed, Neron's deal with Ray is immediately invoked. He's expelled from Ray's body, banished back to Hell by Constantine, and Ray's soul is restored.
When a horrified Zari witnesses Nate's death from the Waverider she rushes to be with him. In a move that showcases the show's signature combination of wackiness and heart, the Legends, the Minotaur, and the Ogre band together to lead the crowd in a sing along of James Taylor's “Sweet Baby James.” Constantine uses the love and warmth generated by the sing along and Tabitha's powerful mystical staff to reunite Nate's soul with his body, saving the hero's life.
It's not a completely happy ending, though; as soon s Zari steps out of the temporal protection of the Waverider, her and the Legends' history is changed. Nate hugs her, and suddenly she's replaced by her brother who joined the Legends in the newly-created timeline. What kind of role will he play on the team, and will Nate and the other Legends remember Zari? Those questions will most likely be touched on in “Crisis on Infinite Earths,” because while the Legends will be a part of the fall crossover, Season 5 won't air until next year.
When the Legends do return, they will face a completely new set of foes. In the finale's final moments, we see Astra Logue make a large withdrawal from Hell's soul bank, sending the souls of some of history's greatest villains, like Genghis Khan and Charles Manson, back up into the world of the living. It looks like the Legends will move from battling mystical monsters to human ones, and when you combine that with the show's penchant for insanely imaginative antics, screwball humor and heartfelt moments, you have the recipe for an exciting new threat -- or the return of an old one...