'Flash' Reveals Grodd's Return in 'Attack on Gorilla City' Synopsis

It’s been some time since we first learned that The Flash would take a two-part trip to Gorilla City, though only now, with Iris’ future hanging in the balance, do we learn what makes Season 3 go ape. Our first synopsis for the “Attack on Gorilla City” has arrived, revealing both a kidnapping, and a surprising alliance.