Fiona prepares for a visit from her probation officer and must rid the house of all suspicious items – a mission that puts her directly at odds with Debbie and Carl. Meanwhile, Ian gets kicked out of Mickey's house by a hammer-wielding Svetlana (guest star Isidora Goreshter), and finally makes his long-awaited return to the Gallagher house.
In detention, Carl shares a connection with a troubled girl named Bonnie (guest star Morgan Lily). Lip grows close to his roommate's now ex-girlfriend, while Debbie sets out to make life miserable for the new girl in Matty's life. Sheila returns from her trip to the reservation with big plans to adopt the Native American kids. Fiona experiences the struggles of job-hunting with a criminal record, while Mickey ignores the birth of his son to spend time with Ian, whose behavior is becoming increasingly erratic.
Fiona goes off the rails – violating multiple terms of her probation by partying with Robbie's degenerate friends. When the family doesn't hear from her, it sends them into search party mode, not too unlike their past experiences with Frank.
Fiona is hauled away to a rough correctional facility as Frank wakes up from his operation suffering from post-operative delirium. Meanwhile, Ian is annoyed at the lack of commitment he sees from Mickey and delivers an ultimatum. After meeting Amanda's parents, Lip makes a decision that he hopes will help his family while also keeping his new 'girlfriend' happy. Debbie meets an older student, Henry (guest star Austin Abrams), who has a dark ulterior motive.
A more cognizant Frank begins to recuperate from his liver transplant, as Sheila fights for custody of the Native American kids, and clashes with Sammi about where they will all live once Frank is released. Meanwhile, Lip catches up on bills. After Fiona passes a drug test and returns home, her parole officer Gayle (special guest star Regina King) finds her a job at Patsy's Pies. Also, Carl is heartbroken when he is deserted by Bonnie. Frank is feeling like his old, troubled self.
In the season five premiere, it's summertime again in Chicago. Fiona balances her job at Patsy's Pies with a crush on her older boss, Sean (Mulroney). After saying goodbye to college and Amanda (recurring guest star Nichole Bloom), Lip heads back home where he struggles to fit in with his old Southside friends. But he's not the only thing in the neighborhood that's changing. With realtors buying up property, there's even a new trendy yoga studio that's popped up. Meanwhile, Frank, still recovering from his liver transplant, is living at Sheila's and working on a secret project in her basement, while Sheila (Cusack) works upstairs to get rid of a problematic Sammi (Bergl) and Chuckie (guest star Kellen Michael).
Fiona is finally officially off house arrest, while Lip starts his first day of work for Tommy (recurring guest star Michael Patrick McGill). But manual labor turns out to be much harder for Lip than he thought…and the brutal hazing from his co-workers certainly doesn’t help. Meanwhile, a manic Ian plans his revenge against a homophobic military funeral protest with Mickey and Mandy Milkovich (recurring guest star Emma Greenwell).
The gentrification of Chicago's Back of the Yards neighborhood continues as Frank enlists Carl to scare off potential investors who are buying up more property in the neighborhood, while pleading with Sheila not to cave and sell her home. Meanwhile, Frank sets the owner of a junkyard up with his daughter, Sammi under shady pretenses in exchange for new brewery equipment.
When Frank arrives at Lou's to pick up his six-figure insurance settlement, he's shocked to discover that he's already collected it. Meanwhile, Lip visits Amanda and her family at their luxurious house in Miami.
Fiona and Gus must navigate the awkwardness of their quickie wedding. But Fiona's plans to announce her marriage at a family dinner become unraveled when her coworker Jackie OD's on heroin. Meanwhile, Frank, who promised an irate Sammi a new trailer once he got his insurance money, avoids her by staying with the still grieving family of his donor liver.
Fiona is thrown into chaos by the return of Jimmy/Jack/Steve, but she must deal with an even larger crisis first as Ian, in a full psychotic break, steals Mickey and Svetlana's baby, Yevgeny, and takes him along on a road trip. But Jimmy is relentless in his pursuit of Fiona who, despite her recent nuptials, eventually gives into their fiery chemistry and long history.
William H. Macy
Frank Gallagher
Emmy Rossum
Fiona Gallagher
Ethan Cutkosky
Carl Gallagher
Shanola Hampton
Veronica Fisher
Steve Howey
Kevin Ball