Flash v. Arrow
Yup, that's The Flash on Arrow. This is a photo from the back half of the crossover event.

Photo Credit:
The CW
Arrow Season 3 Episode 8: "The Brave and the Bold"
Related Photos:
Arrow Photos, Arrow Season 3 Episode 8 Photos
Uploaded by:
Show Comments

Arrow Season 3 Episode 8 Quotes

Caitlin: We had some vacation days...
Cisco: We want to see the Arrow Cave.
Felicity: We don't really call it that. Ever.
Cisco: I want to see the toys. I need to see the toys. Do you guys have an Arrowmobile?

Diggle: If this is an ARGUS thing, Lyla's gonna want it to stay that way.
Oliver: Then tell her to stop letting people get killed in my city.
Diggle: You really don't care about my marriage, do you?
Oliver: Well I would, if you and Lyla were still married.