Izzie continues helping to plan Derek and Meredith's wedding in spite of her cancer treatments; things don't go smoothly when Callie introduces Arizona to her father; Owen seeks out help for his post-traumatic stress disorder.
All reassess their personal lives after witnessing a chance reunion between two long-lost lovers in the emergency room; Karev treats a troubled teen; Meredith shares her suspicions with Cristina.
Michael collapses and must go to the hospital, Sucre steps on a landmine, Mahone meets up with Scylla's designer, and Trishanne has a surprising secret.
With Gideon missing and Hotch and Prentiss off the team, the BAU tackle one of their trickiest cases, a Milwaukee serial killer who uses his son as bait to ensnare women in broad daylight.
Violet finds the perfect couple to adopt her baby.