Warning: spoilers ahead for the first two episodes of the "Crisis On Earth-X" superhero crossover.
The big "Crisis On Earth-X" crossover between Arrow, The Flash, Legends of Tomorrow, and Supergirl has officially kicked off on The CW, and the heroes of the Arrow-verse are now facing off against Nazis from the alternate world known as Earth-X. The second episode of the event belonged to Arrow, and it managed to bring back a long-lost character in a pretty twisted way. Tommy Merlyn returned to the Arrow-verse, but he wasn't the same Tommy that Oliver lost way back in Season 1.
The Tommy Merlyn of "Crisis On Earth-X" came over to Earth-1 with a whole bunch of Nazis and other baddies, including Dark Arrow and Overgirl. He was captured at the end of the Supergirl episode and locked up in a cell of the STAR Labs pipeline, although nobody knew who he was at first. His identity was obscured by the mask he wore, which was none other than the mask of Prometheus. This Prometheus wasn't a psychotic Adrian Chase with a vendetta against Oliver. No, the Earth-X Prometheus was Tommy Merlyn. Oliver had to face off against an evil Prometheus/Nazi version of his best friend.
As if it wasn't bad enough that Oliver had to watch a version of Tommy unmasked as Prometheus, Tommy went on to lead Oliver to believe that he could be redeemed from his role as a bad guy of Earth-X. For a bit, it seemed like Oliver was convincing Earth-X Tommy to do the right thing and turn on his Nazi pals. He even told the story of how Earth-1 Tommy gave up his life to save the woman he loved. Tommy turned in a pretty great performance as he broke down, seemingly torn between fear that his family on Earth-X would be targeted and his desire to help the innocent people of Earth-1.
Naturally, because Oliver can't seem to go more than a few days without some kind of emotionally traumatizing event befalling him, Tommy broke character and began to laugh in Oliver's face, mocking him for believing that he could change Tommy. After all, Earth-X Tommy's best friend was Earth-X Oliver, and Earth-X Oliver is definitely a bad guy. Tommy went on to promise that Earth-X Oliver would kill Oliver's loved ones in brutal ways that would even "give monsters nightmares." Then, to make things worse for poor Oliver, Tommy decided that he couldn't allow himself to be held alive, and he killed himself via poison that he had on him. Oliver had to watch Tommy die yet again.
On the one hand, it was a lot of fun to see Colin Donnell back as Tommy Merlyn, especially since he didn't reprise the role for the epic 100th episode that seemed to bring back just about everybody else from Oliver's past. On the other hand, it was unfortunate for Oliver that he had to see a version of his former best friend so dark and twisted. After all, he encountered Prometheus Tommy relatively early in the crossover, and he presumably still has a lot of work ahead of him.
You can catch the next two installments of the "Crisis On Earth-X" crossover tomorrow night on The CW, starting at 8 p.m. with The Flash and coming to a close with Legends of Tomorrow at 9 p.m. After the crossover is completed this week, Arrow will return to its regular time slot on Thursdays at 9 p.m. ET. For when some of the biggest TV shows will be back on the airwaves in the new year, check out our midseason TV premiere guide.