Executive producer Marc Guggenheim teased several details about what fans should look forward to on the 100th episode of "Arrow" that will air in its fifth season.

Guggenheim talked to the press to discuss the upcoming action-packed crossover episode that will tie "Arrow" with "The Flash," "Legends of Tomorrow," and "Supergirl." According to the executive producer, all the superheroes will find themselves battling the highly advanced race of aliens called the Dominators.

Guggenheim said during the interview that was published by Entertainment Weekly that the superheroes will realize that they need an alien to help them fight the Dominators. "Fortunately, Barry knows a really nice one. I don't think it's a big shock that between Barry and Cisco, and all their experiences with Earth-2 and the multi-verse, that they can pluck her from Earth-CBS," the executive producer also stated.

He also revealed that the events of the crossover episode will be introduced at the end of an upcoming episode of "Supergirl" season 2 when Barry (Grant Gustin) and Cisco (Carlos Valdes) asks Kara (Melissa Benoist) for help. But he explained that the beginning of all the action will happen on "The Flash" season 3. It will then culminate on "Legends of Tomorrow" season 2. But the build-up of the conflict will happen in "Arrow" season 5.

The 100th episode of "Arrow" will also feature the return of some of the show's original cast members including Jamey Sheridan as Robert Queen, Susanna Thompson as Moira Queen, and Katie Cassidy as Laurel Lance. Two of Oliver Queen's (Stephen Amell) biggest nemeses, Malcolm Merlyn and Damien Darhk, portrayed by John Barrowman and Neal McDonough, respectively, will also reappear to celebrate the show's milestone episode.

Also, Guggenheim teased that the upcoming 100th episode of "Arrow" will showcase Amell's most amazing performance to date. "This one scene, that really has two moments within the one scene, it will break your heart. It will take your heart, pull it out, and stomp it on the floor. It's very, very affecting. It's all on Stephen's back," the executive producer stated.

The title for the 100th episode of "Arrow" is still a mystery, but the episode is slated to air on Wednesday, Nov. 30, on The CW.