During the course of their continuing sexual relationship where they do it anywhere they can on unofficial breaks during the school day, Lenny notices a lump on Cathy's lower back side. Dr. Todd's diagnosis is that the cancer is showing itself, but that it does not necessarily mean that the cancer is getting worse. As it is purely a cosmetic issue, Cathy can choose to leave the lump or have it removed. She chooses the latter, and asks the only person who knows, Marlene, to pick her up after the surgery. The lump makes Marlene try to convince Cathy to tell her family about the cancer. It makes Cathy reevaluate her sexual relationship with Lenny and think about bringing her family back together, which includes not only Paul but also Sean. She figures that entering the family into a charity bathtub race, a race they used to always participate in and enjoy, but which Cathy stopped doing because of all the work involved on her end, is a good start. Some news from Paul, and Andrea finding out about Cathy and Lenny could bring Cathy's current plans crashing down around her.