Officer John Nolan is forced to spend a week in solitary confinement in a quiet border town with a young local officer who is in need of some training. Meanwhile, Sergeant Bradford and Officer Chen discover that looks are deceiving and go undercover together in a possible drug trafficking case.

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.