Meredith, Arizona, and Minnick are all in the parking lot of the hospital when suddenly there's an explosion from an upper floor. They rush to help, but are stopped at the door by security because of the hospital lockdown. Chief Bailey appears and demands the three doctors be allowed in. 'Fire in the hospital trumps rapist on the loose! They are cleared!' she shouts. Watch this sneak peek from the Season 13 finale, 'Ring of Fire' and don't miss Grey's Anatomy THURSDAYS 8|7c on ABC.