Question: where are all the episodes of crisis on earth x?
Answer: Supergirl, Season 3 Episode 8 (aired on Monday night, 8/7c)
Arrow, Season 6 Episode 8 (aired on Monday night, 9/8c)
The Flash, Season 4 Episode 8 (airing on Tuesday night, 8/7c)
Legends of Tomorrow, Season 3 Episode 8 (airing on Tuesday night, 9/8c)