A blast from the past shakes up Fiona's view of her life. Frank gets involved with Liam's school and becomes the most popular dad in the PTA. Lip learns getting laid is harder than anticipated when sober. Ian crosses a boundary with a kid from the youth center. Kev and V take a trip to meet his birth family.

Election day puts Frank and Fiona in a head to head battle as they each try to round up votes for their candidates. Lip has to make an important choice about Xan’s future. Debbie gets in over her head with Alex. Carl’s killer instinct is put to the test. With his trial looming, Ian struggles to decide how to plead. 100th episode!

Frank’s new liver medication comes with tragic side effects. Ian tries to get away from Fiona’s hovering. Lip has to keep himself occupied during a day of temptation. Carl makes a connection at a West Point mixer. Debbie tries to repair things with Alex.