"A" almost kills Mona. Meanwhile, Aria takes self-defense lessons; Alison's mom gives Hanna a parrot; Toby reveals a poignant secret to Spencer; and Hanna uncovers something surprising about her mother.

A new detective arrives in town and questions the girls about Wilden's death. Meanwhile, Emily worries about the problems "A" is causing for her parents; Hanna is reluctant to accept Caleb's help; and Spencer sets a trap for her sister.