Sunday night's new episode of Tracker brought an important guest star and a potentially important character into the mix. Star Justin Hartley was joined in the episode by real-life wife Sofia Pernas, who played Billie, a former partner and love interest of Colter's. In "Lexington," the two characters run into each other for the first time since Billie left Colter high and dry at the end of a job five years prior. With both of them now working on the same case, they decide to join forces to get the job done, and it brings some romantic feelings back to the surface. The final scene of the episode delivers something of an open ending when it comes to their relationship. WARNING: This article contains spoilers for Tracker! Continue reading at your own risk...