On tomorrow night's Grey's Anatomy, the "Invasion" is underway.

The episode title is an appropriate one, given the swarm of highly suspicious new doctors from Mercy West descending on Seattle Grace. The merger is in full, awkward swing.

In the first sneak preview, Meredith talks about the evil, invading "others" who have come to take their jobs, and how the Seattle Gracers are not going to be pushed around!

She's been watching a little too much TV while stuck in bed ...

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Follow the jump for six - six! - more clips from "Invasion." Another, wholly unrelated invader is also arriving - Callie's dad. She is pissed. Arizona oddly tells Callie to cool it.

Also, our gang interacts and does passive-aggressive battle with the newcomers, including guest stars Sarah Drew and Nora Zehetner. Watch, enjoy, and comment below ...

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Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.