Having received an ominous threat from her old boss, Amunet, Caitlin fears that her past time as Killer Frost may be back to haunt her. Felicity comes to Central City to help the girls celebrate Iris's bachelorette party, while Cisco, Joe and the guys take Barry out for a night on the town.
- This is the first episode in which Barry appears only as a civilian and not as the Flash.
- In mentioning how she's always wanted a sibling, Joanie notes how seven Doctor Whos later it happened.
- Joanie tells Joe that she became a Doctor Who fan after the protagonist became a woman, referencing the upcoming real-life portrayal of the Doctor by Jodie Whittaker.
- Cisco describes photos of baby Barry as having "Ewok-level chub", referencing the species of furry bipeds from the Star Wars franchise.
- When Ralph goes to describe the West house, Cisco suggests "bitchin'", referencing Barry's encoded message in "The Flash Reborn".
- Harry refers to Ralph as "Disney", referencing the animated film company.
- Felicity references the Marvel character the Incredible Hulk in comparing Killer Frost taking over Caitlin's mind.
- This is the first episode in which Barry gets drunk. Since his super speed makes regular alcohol have no effect on him, Cisco had to concoct a special drink for him that could overpower his fast metabolism for his bachelor party. Caitlin had previously tried to make him a drink that would be strong enough in "Plastique", but failed as its effects only lasted a few seconds.
- When Barry is drunk, he asks Joe why Rose didn't make room for Jack on the door, referencing the climactic scene of the 1997 film Titanic, and its protagonists Jack Dawson and Rose DeWitt Bukater.
- ↑ Flash “Girls Night Out” Description: Emily Bett Rickards & Katee Sackhoff Guest Star - FlashTVNews
|The Flash season 4|
|"The Flash Reborn" • "Mixed Signals" • "Luck Be a Lady" • "Elongated Journey Into Night" • "Girls Night Out" • "When Harry Met Harry..." • "Therefore I Am" • "Crisis on Earth-X, Part 3" • "Don't Run"|
|"The Trial of The Flash" • "The Elongated Knight Rises" • "Honey, I Shrunk Team Flash" • "True Colors" • TBA • "Enter Flashtime"|