'Crisis on Earth-X' has given fans a new look at plenty of heroes and villains - including one surprising twist on an Arrowverse favorite.
Spoilers for the first and second installment of 'Crisis on Earth-X' below!
After the villains of Earth-X crashed the wedding of Barry Allen/The Flash (Grant Gustin) and Iris West (Candice Patton), the Arrowverse's heroes captured the Earth-X version of Prometheus in S.T.A.R. Labs. They kept him in a containment cell, where he very quickly revealed his identity - Earth-X's Tommy Merlyn (Collin O'Donnell).
Earth-X Tommy then had a conversation with Oliver Queen/Green Arrow (Stephen Amell), where they reflected on how drastically different their lives are from each other. Tommy told Oliver what the other Earth-X villains have planned - conquering Earth-1, and enslaving or killing all of those within it. Tommy then lamented that he won't be around to see it, and killed himself by swallowing a cyanide capsule.
If you're unfamiliar with Tommy (or, well, the Earth-1 version of him), here's a crash course. Tommy served as a core element of Arrow's first season, both as the best friend of Oliver, the boyfriend of Laurel Lance (Katie Cassidy), and as the son of Malcolm Merlyn (John Barrowman).
To the shock of many Arrow fans, Tommy died in the closing moments of the show's season one finale. When Malcolm Merlyn initiated an undertaking throughout one of Starling City's neighborhoods, Tommy and Oliver both flocked to save Laurel. Tommy ended up getting trapped inside a building, with Oliver staying by his side until he dies.
While Tommy's main Arrow arc wrapped up then, his spirit has carried on throughout the show. Oliver continued being a hero as a way of honoring Tommy's memory (something he reflected over and over again on the season's intro narration). And O'Donnell did have a hand in some of Arrow's later installments, appearing in a season three flashback and getting a pretty fantastic name-drop in last year's 'Invasion!' crossover.
But having a version of Tommy return as Prometheus is something else altogether - mainly because fans have been campaigning for it for quite some time. Last season, some hoped that Tommy would return back to life on Arrow, thanks to The Flash changing the timeline in "Flashpoint". This turned into pretty frequent speculation that Tommy was Earth-1's Prometheus, the masked foe who appeared to have some sort of vendetta against Oliver.
Ultimately, this ended up not being true, as Prometheus was revealed to be Adrian Chase (Josh Segurra). But Tommy being Earth-X's Prometheus does give some fans what they've been hoping for, even if it was only for a few scenes.
"Crisis on Earth-X" is a four-hour event that will air on November 27th and 28th beginning at 8 p.m. and running for two hours each day; Supergirl (8 p.m. Monday), The Flash (8 p.m. Tuesday) and Legends of Tomorrow (9 p.m. Tuesday) will remain in their normal time slots but Arrow will move from Thursday to a 9 p.m. Monday placement for the week.