Two firehouse members are abducted, triggering a desperate search by the Chicago P.D. Elsewhere, Casey and Dawson struggle to balance their personal and professional lives, and Chief Boden deals with news that his newborn has potential complications.

Severide and Dawson unearth shocking evidence about the fire that killed Shay. Elsewhere, the firehouse bonds over a serious car accident, and Chief Boden's father visits, only to give unsolicited parenting advice.

Additional clues about Shay's death emerge. Meanwhile, Severide faces an old foe; Shay's sister arrives, inspiring the firehouse members to reflect on her life; Otis' grandmother relocates; and Boden sets out to help his dying father.

The crossover continues on Chicago P.D. S02E13 A Little Devil Complex (II).

An ice storm hits, forcing a citywide lockdown. Mills and Brett are left stranded in the elements while searching for a teen, and the firehouse members babysit a newborn. Elsewhere, Severide receives a job offer, and Chief Boden clashes with his father over his treatment.