Supergirl season 1, episode 18, “Worlds Finest,” featured an absolutely delightful crossover with The Flash.

The highly anticipated crossover between Supergirl and The Flash was about as joyful as you’d expect it to be. In fact, my biggest criticism is that I wanted to spend more time with Barry and Kara and their incredible chemistry — time that was obviously limited by Grant Gustin needing to film two shows in two countries across two channels.

Gustin and Melissa Benoist are simply a joy to watch together. The Flash is the lightest hero in the Arrow-verse and Supergirl is light in her own right, so putting them together feels natural, as though they belonged together all along. This is in contrast to the crossovers between The Flash and Arrow, which features significantly more conflict; the first crossover between these two shows saw the Arrow and Flash fighting, first because Barry had his own “Red Kryptonite” experience (which he referenced in this episode) and then just for the fun of it.

The Flash and Supergirl, on the other hand, eat ice cream and donuts and team up to defeat bad guys. It’s exactly as much fun as you want it to be with these two characters.

Something else that was fun to see was Barry acting as a mentor to Kara; Barry’s been a superhero for nearly two years while Kara is coming into her own and getting out of the shadow of her cousin. While Oliver has been the grizzled veteran of the Arrow-verse, it’s nice to see Barry get to share some advice based on his own experience. He’s kind and supportive when giving Kara advice, and it’s what she needs to hear.

Winn, humorously, is completely taken with Barry and wants to be his best friend. We need to see Winn and Cisco together in the future.

Undoubtedly this will end up being a refreshing experience for Barry since he’s been going through his own issues on The Flash that have sent his own life spinning the way Red Kryptonite has for Kara. While we don’t see how Barry gets to Kara’s Earth or what’s up with the new device on his chest, Greg Berlanti promises that we’ll see the setup as well as the aftermath in Tuesday’s Flash episode.

This episode also sees James struggling with his feelings toward Kara. He wasn’t ready to hear Kara’s feelings for him, but he immediately becomes jealous when Barry flashes (haha) into Kara’s life. Multiple people (Cat, Lucy and even Barry, who knows a thing or two about not being with someone he loves) comment on the dynamic between Kara and James. Eventually, Kara kisses James and it looks like we might finally get the romance the season has been building toward…

Until James, blank-faced and emotionless, joins the masses of the city marching in the streets. The Kryptonians have activated Myriad. Non is always killing the mood.

Speaking of villains, we see the conclusion of Siobhan’s evolution (or devolution?) into Silver Banshee, as it turns out her powers come from a curse from her family’s days in Ireland. She must kill the person who has wronged her or let the powers take her over. Siobhan breaks Livewire out of the DEO and the two team up to kill Cat Grant, Supergirl, and Kara.

Too bad for them they chose the day there was another superhero in town to act.

Barry eventually gets back to his own Earth when he and Kara join forces to get Barry going fast enough to travel across universes. Their hug before Barry goes is downright adorable, and if there aren’t more crossovers in the future, it will be a shame.

Moreover, this episode sees Supergirl winning back the trust of the people of National City. When Livewire tries to take down a helicopter, Supergirl gets in the way and takes the lightning herself, which seriously hurts her. The people who have gathered to watch make the choice to protect her, having seen Supergirl protecting them, and it’s eventually firefighters hitting Livewire and Silver Banshee with a fire hose that takes the villains down.

It’s perhaps a bit sudden, though to be fair it might just be the people who witnessed the fight that have been won over. It would make more sense if most of the city was still wary of her. After all, most of the work Kara’s done to win people back has seemingly been done off-screen, and it would make a lot of sense for Kara saving everyone from Myriad to be what tips the scales back in Supergirl’s favor.

Overall, the episode was nothing short of a joy to watch, and future crossovers are a must.

What did you think of ‘Supergirl’ season 1, episode 18, ‘Worlds Finest’?