After several of Bailey's patients die, she becomes the focus of a CDC investigation; Cristina teases Alex about his feelings for Jo; Owen continues to take care of Ethan while his parents remain in the hospital.
Castle is abducted and forced to solve deranged puzzles and mind games with strangers; Beckett and the 12th precinct race to save Castle.
Pete and Violet go to a marriage counselor; Amelia gets some devastating news; Mason refuses to speak to Charlotte and Cooper; Violet suspects the sister of one of her patients.