The fifth and final season of Boardwalk Empire follows embattled Alantic City politician Nucky Thompson (Steve Buscemi) as he confronts the demons of his past and strengthens his foothold in smuggling goods illegally back and forth from Cuba. Elsewhere, gangster Al Capone's behavior becomes increasingly erratic as the feds close in, and Chalky White struggles to evade law enforcement and avenge the death of his daughter.

Duncan's (Ken Marino) life is a real pain in the ass. Tormented by a manipulative, crooked boss (Patrick Warburton), a nagging mother (Mary Kay Place) with a boyfriend 1/3 her age, a deadbeat new age dad (Stephen Root), and a sweet, yet pressuring, wife (Gillian Jacobs), his mounting stress starts to trigger an insufferable gastrointestinal reaction. Out of ideas and at the end of his rope, Duncan seeks the help of a hypnotherapist (Peter Stormare), who helps him discover the root of his unusual stomach pain A pintsized demon living in his intestine that, triggered by excessive anxiety, forces it's way out and slaughters the people who have angered him. Out of fear that his intestinal gremlin may target it's wrath on the wrong person, Duncan attempts to befriend it, naming it Milo and indulging it to keep it's seemingly insatiable appetite at bay.