Rick Worthy, Kevin McKidd

Prepare for a terror-filled season finale of Grey's Anatomy!

Cryptically titled "Fear (of the Unknown)," the Season 10 finale finds the doctors of Grey Sloan Memorial Hospital treating the victims of a possible terrorist act that causes chaos at the hospital. That's right, Cristina (Sandra Oh) leaving the hospital won't be the toughest part of the finale! Check out our exclusive first looks at the season finale:

Get the scoop on 39 must-watch finales

Grey's Anatomy airs Thursdays at 9/8c on ABC. The season finale is set for Thursday, May 15. Missed an episode of Grey's? Watch full episodes here.