With The CW’s DC shows of Arrow, The Flash, Legends of Tomorrow, and Supergirl confirmed for a four-way crossover event in December, now comes some news on just what threat will bring these heroes together.

Previously, it was believed that the Legion of Doom may be the force that brings together some of DC’s finest. After all, the team – made up of Damien Darhk, Reverse-Flash, Malcolm Merlyn, and Captain Cold – are already confirmed to be causing chaos in Legends of Tomorrow’s second season. But no, it will be the presence of the villainous Dominators that will see the Emerald Archer, Sultan of Speed, Maid of Might, and Rip Hunter’s Legends team working in unison.

Executive producer Marc Guggenheim revealed, “This year, for our mega ‘Arrowverse’ crossover, we’re taking inspiration from a DC crossover from the late 1980s known as Invasion!, which featured an alien race called the Dominators, who’d previously vexed the Legion of Super-Heroes. We’re using cutting edge prosthetics and computer effects to achieve a feature film-quality look which is faithful to Invasion! artist Todd McFarlane’s interpretation of the characters.”

The Dominators are an alien race driven by advanced technology and with one eye on wiping out the human race.

All four of Arrow, The Flash, DC’s Legends of Tomorrow and Supergirl return to screens next month.