In case you need a refresher, Jack and Cathy first met at her father's birthday party in season one. They hit it off initially, but then they hit a road bump because of Jack's failure to be completely honest with her about his job. Fortunately, it didn't destroy their relationship. But by the end of season one, their future together felt uncertain—especially since Greer (Wendell Pierce) saved her life towards the end and not Ryan.
Even so, we expected to see Cathy return and further explore this new romance with the analyst-turned-action hero. But we got the biggest surprise when, in the very first episode of season two, Jack morphed into James Bond 2.0, claimed to be single and slept with Harriett (Noomi Rapace) the first chance he got. Mind you, there was zero mention of Cathy, let alone how her relationship with Jack supposedly ended.