One of Jane's tattoos sends the team to a remote location where they find themselves face to face with a dangerous criminal in a case that puts Jane and Weller's strained relationship to the test and threatens to expose Mayfair's secrets. Meanwhile, Patterson breaks the rules to solve a tattoo puzzle.

Jane and Weller go undercover as a world-class assassin couple to prevent deadly information from getting into the wrong hands. The intimate assignment draws them closer than ever. Meanwhile, David embarks on a solo mission to win Patterson back, and Carter clashes with Mayfair over how to handle a dangerous individual.