The team comes together to celebrate John and Bailey's wedding; meanwhile, Celina discovers a discrepancy in her case, leading to a new discovery. Elsewhere, Lucy and Tim's relationship is put to the test.

It's Officer Aaron Thorsen's first day back since the assault, and he's tasked with a series of high-stress cases to determine whether he's ready to work. Elsewhere, the team investigates a homicide case with a potential tie to the pentagram killer.