After Hal and Lois leave town for a getaway, "squatters" crash Reese's party, take over the house and refuse to leave.
The team searches for a serial killer who is preying on married couples; Hotchner looks to a team member to fill JJ's vacant role.
J.D. and Drew learn a tough lesson in mentoring when Dr. Cox and Lucy show them that the student is sometimes the teacher.
When Louis and Jessica are pressured into volunteering due to budget cuts at school, the kids see a new side of their parents.
Ellie tricks Jules into baby-sitting on her own for a day; Bobby gets a chance to play golf for free; Andy offers to be Laurie's wingman.