Supergirl, Flash crossover clip explains multiverse

Still don't really understand the concept of the multiverse in the world of The Flash? Well, Barry Allen (Grant Gustin) offers up a free science lesson in a new clip from the crossover episode with Supergirl.

The footage released by CBS shows a scene in which Jimmy (Mehcad Brooks) and Winn (Jeremy Jordan) try to wrap their head around the fact that a being from another Earth is standing in front of them. Thankfully, Kara (Melissa Benoist) has the scarlet speedster to explain the concept — and with visuals!

WANT MORE EW? Subscribe now to keep up with the latest in movies, television and music.

The crossover episode sees Barry helping Kara battle the villains Silver Banshee and Livewire in exchange for help returning to his Earth. The action will commence on Monday at 8 p.m. ET on CBS, and EW has the scoop on everything you need to know beforehand.