WARNING: The following article contains minor spoilers for this week's episodes of The Flash and DC's Legends of Tomorrow, parts 3 and 4 of "Crisis on Earth-X," which debuted tonight on The CW.
This year's Arrowverse crossover, "Crisis on Earth-X," was dotted with pop-culture references -- much to the delight of Cisco Ramon -- from Raiders of the Lost Ark to The Terminator. But the two-night event saved its best nod until its final hour: a tribute to the 1980 classic Superman II.
Reeling from a major loss but resolved, with the help of their new allies Citizen Cold and The Ray, to defeat the Nazi invaders from Earth-X, the heroes of the Arrowverse engage in an epic battle for the fate of Central City, and the planet. When their effort to shoot down the Nazi version of the Waverider fall short, they're forced to call in "a bigger gun" -- Supergirl, fully recharged after spending much of Part 3 in a weakened state, and itching to fight her evil doppelganger Overgirl, a general in the Fuhrer's army.
That last detail is important. The moment arrives about midway through DC's Legends of Tomorrow, as Overgirl is informed by one of her subordinates aboard the Nazi Waverider that "we've got inbound," hovering directly off the bow. It's Supergirl, floating just outside, her arms confidently crossed. "General," she says. "Would you care to step outside?"
It's, of course, an ode the scene in Superman II in which Christopher Reeve's Man of Steel dramatically arrives at the Daily Planet to challenge the Phantom Zone villains General Zod, Ursa and Nod who, in his absence, were wreaking havoc.
It's impossible to say how long the Arrowverse writers were building toward that moment, but we'd like to think it was the instant they decided to make Overgirl a general. Alas, they stopped short of the Nazi doppelganger demanding that Supergirl "kneel before Overgirl!"
There's no icy final showdown at the Fortress of Solitude, either, but naturally Kara does defeat Overgirl and save the day, with some prompting from Harrison Wells to fly "up, up and away." Like, out of Earth's atmosphere.
Airing Tuesdays at 9 p.m. ET/PT on The CW, DC' Legends of Tomorrow stars Caity Lotz, Brandon Routh, Tala Ashe, Franz Drameh, Maisie Richardson-Sellers, Nick Zano, Amy Pemberton, Dominic Purcell and Arthur Darvill.