Lara Phillips

The team tracks a serial killer when remains of numerous victims are found in the walls of an elderly couple's home; the hunt becomes urgent after the BAU learns the killer's specific ritual of when to strike; Rossi reconnects with his ex-wife.

Alex gains the trust of Annie, a nervous patient with an extraordinarily large tumor, only to humiliate himself in front of her later. Meanwhile Derek chooses Meredith to assist with an elderly Parkinson's patient who may need surgery -- but Bailey disapproves of their relationship and is determined to make Meredith suffer -- and tensions escalate between Burke and Shepherd.