“Girls Night Out” is episode five of season four of The Flash.
Ralph is testing his stretching and Barry is asking Cisco and Harry if they have anything on DeVoe, who Ralph said was his client in the previous episode, “Elongated Journey Into Night”, and who Barry had been told would be one of his greatest foes. There are thousands of DeVoes in this state alone.
Felicity arrives and Barry asks how she got in. She walked in. They have no security. She thinks they really should get some. Felicity is going on Iris’s bachelorette party and starts talking about divorce stats as Harry waves her to shut up in the background. She leaves to find the others.
Caitlin is looking at a plane ticket she’s booked when Iris and Felicity find her. She’s not feeling up to it, but is talked into going out.
At Joe’s, Cecile is talking to her daughter, Joanie, when Harry, Cisco and Barry arrive for the bachelor party. Cecile is heading out to join Iris and invites Joanie, but Joanie is busy. Cisco is showing home videos of Barry when Ralph arrives. Ralph discovers this is Barry’s bachelor party and isn’t impressed. He has a better idea for somewhere they can go and eat.
The bachelorettes are at a fantasy restaurant when a thug Caitlin knows shows up. The other three think he might be a stripped. Then one of his eyes pops out and a grasping snake thing emerges. Caitlin asks him not to do this, then turns into Killer Frost and blasts him through the window.
Going by Ralph’s description, it’s not a great surprise to find he’s taken them to a pole dancing club. They have to surrender their phones. Barry wants a drink and Cisco has made him a concoction. Iris, now their phones are gone, is trying to ring.
Back at S.T.A.R. Labs, Killer Frost says she’s going to find the man, Norvok’s, boss and kill her. The other three leave to let her get changed and Iris is more willing to take a chance on Killer Frost than the other two. However, they agree to help and Felicity will track Frost.
At the club, Barry is drunk and telling everyone he’s the Flash. Cisco thinks he might have miscalculated the formula. Harry has been talking to the dancers and is impressed how much they make. Then a new one gets on stage. Joanie.
Killer Frost has gone to a club and finds the owner, Amunet Black. Killer Frost says she’s out but Amunet has something that can make them very rich. The other three arrive and turn down the offer of a glowing drug. Iris sees Norvok and follows.
Amunet has a meta called Weeper that she found three weeks ago. When he cries, he produces the glowing drug. Amunet plans to spread it around Central City and wants Killer Frost as protection. For a percentage. Killer Frost isn’t interested and the two are facing off when Iris intervenes to stop a fight that would destroy the club.
Though neither party goes as expected, there is a lighter tone to the episode. And Joe is worrying about impending fatherhood.