[WARNING - This review contains SPOILERS for The Flash season 4, episode 5.]

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The Flash season 4 has been all about fun, fun, fun, with each episode delivering lots of laughs and zany antics but only the tiniest of updates on The Thinker's evil plan. For the most part, that's made for a more enjoyable start to the season, removing the heavy cloud of dread that has hang over the cast in previous years.

Not really knowing the full scope of The Thinker's scheme has given season 4 lower stakes, and with the looming threat so minimized, we get episodes like 'Girl's Night Out' - a Flash-free romp in where the boys have a miserable evening for Barry's bachelor party while Iris and the girls handle the serious business. A lot of the episode is just pure, meaningless fluff, but it does finally give an explanation to how Killer Frost will work and allows Iris and Caitlin to bond through their own dangerous adventure.

After only being introduced last week, Ralph Dibny is already a regular at S.T.A.R. Labs and a proto-member of Team Flash (with his first official superhero-outing coming next week). How quickly he's been made one of the gang leads to Ralph crashing the low-key bachelor party Cisco had in mind for Barry, taking their "see you later" as an open invitation to join. Thank goodness he does because as sweet as Cisco's intentions were, getting to see the men of Team Flash at a strip club is a hoot. Naturally, Ralph is a regular at the establishment, hence his insistence they go there, and the whole scenario lets him play up that sleaziness. It's clear we aren't meant to really like Ralph, not yet anyway, but it's refreshing to have him there to shake things up.

And shake things up he does, because arriving at the strip clubs leads to Cisco giving Barry another one of those concoctions that lets him get good and drunk. The Flash has certainly done drunk Barry before, but it's never been funnier than him screaming "I'm the Flash!" or sobbing into a basket of chicken wings. Since he never actually suits up as The Flash this episode, seeing him set loose is a welcomed break for Barry (and us). Joe's arc is more serious, as his fear over the new baby sets in, but it leads to a very sweet exchange where Barry assures Joe he won't be raising this kid alone. (Cue those Flash Family feels!) This lovely moment comes while they're sitting in a jail cell and Barry's got his head in a toilet, just in case you forgot what a disaster the bachelor party is, but here their misery is our comedy. Plus, Harry continues to be the king of the one-liner, and in this episode he has some of the best.

The bulk of 'Girls Night Out', fittingly, follows Iris, Caitlin, Cecile, and Arrow's Felicity as they start out having a nice dinner at a classy restaurant, only for it to devolve into them battling one of Central City's toughest crime bosses - Amunet (Katie Sackhoff). What really gets the ball rolling here is Caitlin being confronted by one of Amunet's henchmen and letting her Killer Frost out. It's also finally revealed that while Barry was in the Speed Force, she was working as hired muscle for Amunet in exchange for something that let her keep Frost under control. Flash is full committing to Killer Frost existing as a separate identity within Caitlin and it's a good decision, keeping both aspects of her character available for future stories. Largely, she can be Caitlin and continue acting as Team Flash's conscience, but when necessary, the devilishly fun Frost can be unleashed.

With the women taking charge and basically forming their own Team Frost to rescue the meta-human Amunet has captured - named The Weeper for his ability to cry tears laced with super ecstasy (this might just be the weirdest power yet) - Iris takes the lead, displaying her gumption and knack for bossing people around. Sure, some viewers still balk at Iris taking charge in any situation, but it's to the series' credit they put Iris in this proactive role. Four seasons in, Iris is more than experienced at tackling a bad guy or two, and in this episode, she leads the ladies in stopping Amunet and rescuing The Weeper. Granted, they foolishly let Amunet just leave and don't think about monitoring where The Weeper goes after he declines their help, but hey, it's a better look than locking them away in the particle accelerator without a thought towards due process.

'Girls Night Out' does, occasionally, go overboard with its message of female empowerment. That #feminism bit in particular was pretty cringe-worthy. But by and large the episode does feature The Flash's female characters carrying their own adventure and doing it well. This is certainly helped by Sackhoff's deliciously over-the-top performance as the metal-wielding Amunet, who fully indulges in the campy-ness of it all while stealing every scene she's in. She'll be hanging around the Arrowverse for a while, thankfully, so get ready for more.

As is becoming the pattern this season, there was only the briefest appearance from The Thinker as he came to town in that floating chair and scooped up The Weeper for some still unknown purpose. It's just enough to keep us (and Team Flash) aware of his evil-doing, but also keeps the episodes free to more deeply explore the characters and their relationships. That's always been what The Flash is best at, after all, and season 4 is all the better for embracing it so fully.

MORE: Amunet Will Return To The Flash

The Flash season 4 continues next Tuesday with 'When Harry Met Harry...' at 8pm/7c on The CW.