While the rest of DC’s TV universe is invaded by the Dominators, Oliver Queen (Stephen Amell) will be dealing with problems of his own. In the plot synopsis for the 100th episode of Arrow, titled “Invasion!” which will occur during the crossover with The Flash, Supergirl, and Legends of Tomorrow, Oliver wakes up in an alternate timeline where “small imperfections” will make Ollie “question this new reality.”
This reality in “Invasion!” is one where Oliver didn’t board the Queen’s Gambit, the ship that stranded him on Lian Yu where he met Slade Wilson (Manu Bennett). While this would logically mean Oliver doesn’t fight Deathstroke at all, “small imperfections” indicate a sort of merging of the two realities, which could enable Deathstroke to appear.
Bennett has been coy whether or not he’s reprising his role; he’s left out of the official synopsis, he’s teased the crossover on social media, but only guest stars Jamey Sheridan, Susanna Thompson, and Katie Cassidy are credited for reprising their roles (Robert Queen, Moira Queen, and Laurel Lance respectively). Laurel is also engaged to Oliver in this timeline, which means Ollie’s affair with her sister Sara (Caity Lotz) is still kept secret for just an episode.
While Oliver tries to get a grip on reality, the episode synopsis reveals Felicity (Emily Bett Rickards) leads the newest recruits this season — such as Wild Dog and Ragman — in a team-up with the Flash and Supergirl. It’s worth noting that nobody from Legends of Tomorrow is credited for the episode.
There are numerous ways in which Ollie could be in an alternate timeline. While it could be the work of the Dominators, there’s also the universe-altering Flashpoint on The Flash that’s allowed the alteration of events. Although the only change in Arrow so far was minimal — John Diggle’s (David Ramsey) daughter Sara became a son, John Jr. — Doctor Alchemy and Savitar have been toying with people who lived with powers in the Flashpoint timeline. Maybe Alchemy and Savitar have some plans for Oliver all the way in Star City too.
The four-show crossover will begin with Supergirl on November 28.