The Flash Season 3 Episode 8 Invasion!

As the name suggests, the eighth episode of The Flash's third season, "Invasion!," is all about the invasion of the Earth by alien beings called Dominators. The episode, which is part of a four-show crossover event that includes Supergirl, Arrow, and Legends of Tomorrow, sees the aforementioned DC Comics characters teaming up to fight off the extraterrestrial threat.

The episode starts off with Barry and the gang at S.T.A.R. Labs discussing the Dominators and trying to come up with a plan to stop them. However, things take a turn for the worse when a group of Dominators shows up in Central City, demanding that the humans hand over the metahumans (people with special powers) to them. This leads to a fight between Team Flash and the Dominators, which ends with the latter escaping.

Realizing that they need more help to stop the Dominators, Barry and Cisco decide to travel to Earth-38 to recruit Kara Danvers, a.k.a. Supergirl, who is the only known alien on Earth. After convincing her to help, the trio heads back to Earth-1, where they meet up with Oliver Queen (Green Arrow) and his team in Star City.

The rest of the episode sees the five superheroes working together to stop the Dominators and their army of mind-controlled humans from taking over the Earth. Along the way, they encounter various obstacles, including a powerful meta-human who is working with the Dominators, and a message from the future warning of a catastrophic event that occurs as a result of their current actions.

Despite these challenges, the heroes manage to come together and defeat the Dominators, with the help of some unexpected allies. In the end, they return to their respective cities, having formed a stronger bond and a renewed sense of purpose.

Overall, "Invasion!" is a thrilling and action-packed episode that brings together some of DC Comics' most beloved characters in a fight against a common enemy. It is a testament to the power of collaboration and teamwork, and a reminder that even the most seemingly insurmountable challenges can be overcome with determination and a little bit of luck.