Walker, Cassie and Captain James team up to put Trey through the final stages of his training, a "Rangers hell-week" that will ensure he's ready to join the ranks of the elite organization, but it's not only Trey who is put to the test, Walker hasn't worked with Cassie in weeks and both struggle to get their partnership back in sync.

Walker makes good on his promise to Liam to finally discuss captivity, and painful details from the past inform the present to help the Rangers eliminate a dangerous threat. Meanwhile, a new case forces Cassie to confront her aversion to dating.