Crisis on Infinite Earths, Part 3 (2019)
Episode of The Flash

In the third chapter of the Crossover, Black Lightning joins the Arrowverse to help stop the Anti-Monitor, while Oliver & Diggle return to a familiar place. (imdb)
Cast and Information
Season: 6, Episode: 9 - Episode Guide
Directed By: David McWhirter
Written By: Lauren Certo, Sterling Gates
Starring: Danielle Panabaker, Tom Cavanagh, Stephen Amell, Ruby Rose, Caity Lotz, Melissa Benoist, Grant Gustin, Cress Williams, LaMonica Garrett, Carlos Valdes, Candice Patton, Hartley Sawyer
Genres: Drama, Sci-fi, Action, Adventure
AKA: Crisis on Infinite Earths: Part Three
Country: USA