"Sleeping Monster" is the twenty-first episode of the ninth season of Grey's Anatomy and the 193rd produced episode of the series. It is also the 304th produced episode of the Grey's Anatomy franchise. It was broadcast on April 25, 2013.
In the wake of the death of several of her patients, Bailey finds herself at the centre of a CDC investigation and the board members are put between a rock and a hard place when they are forced to walk the line between doing what's best for their hospital and their staff. Meanwhile, with her confidence is shaken, Bailey's relationship with Richard finds itself at a crossroads. Meanwhile, Meredith asks Cristina to be in the delivery room with her when she goes into labour and Jackson finds himself bearing the brunt of the board, and April's, frustrations. Meanwhile, Alex and Jo's relationship faces an unexpected test when she tells him that she's decided to move in with her boyfriend while Owen struggles when Ethan's mother dies leaving him in the custody of his emotionally fragile grandmother.
- "Infections are like sleeping monsters. You can't see them. You can't feel them but you must do everything in your power to contain them. Because when the monsters wake up they're out of control."
- "All that time you spent convincing yourself the monster wasn't real, it was gathering strength. The infection was spreading. The monster's awake now and there's nothing you can do about it."
- "Avalanche" - Zola Jesus
- "Think" - Aretha Frankin
- "Broken" - Jake Bugg
- "Sea Fog" - Keane
- "Say Anything" - Anderson East feat. Jill Andrews
This episode's title originated from the song Sleeping Monster, originally sung by Desert Planet.
- Bailey narrates the voiceover for this episode.