Rosen enlists Alpha tech-whiz Skylar Adams to help to discover the purpose of an Alpha enhancing technology, but Rosen's zeal puts both Skylar and her daughter in grave danger.

Now that Rosen has discovered the identity of the mole, he must face down the nearly impossible choice of what to do next. Meanwhile, the team takes on their individual family issues: Hicks' son Tyler comes for a surprise visit and John gets to meet Rachel's parents. And Kat gets her first case, tracking a mysterious new street drug that makes users temporarily invincible.