When Carrie is invited to a Halloween party in the city by Larissa, she decides to invite Walt to go with her to keep her company. It doesn't take long before the night goes awry and Carrie is forced to babysit Larissa, who has clearly taken too many drugs. Walt finds himself in an uncomfortable position after a party guest gets a little too close for comfort. Elsewhere, Maggie convinces Mouse to go with her to Sebastian's Halloween party at the diner to help keep tabs on him. After Doritt's attempt to sneak out of the house is thwarted, she discovers hanging out with her father isn't so bad.