Mary and Marshall take on a case involving Horst Vanderhoff, an agent for Lola, who's an assassin for hire. While trying to line up her next job, Horst is busted and agrees to testify against her to become a part of the Witness Protection Program.

An engineer blamed for a bridge collapse enters the program after being targeted by angry family members of the victims who died in the tragedy.

Mary helps her latest witness, a homeless man who's struggling with the program, find his birth parents. But the search could cause more problems than she anticipated. Elsewhere, Scott asks to borrow more money, raising a red flag for Brandi.

Mary helps protect a guilt-ridden Army veteran; Marshall & Abigail consider the next step.