A blizzard moves into Chicago, stranding a family in the snow. Pratt, Abby, Hope and Ray must struggle to save the family, and keep hope alive when they learn one member is still missing. Luka's got a problem intern in his sights, and he's not pleased. Later, a gang shooting challenges Luka and Pratt. Meanwhile, Luka and Abby begin making wedding plans, but is their engagement still a secret? Sam makes a difficult choice about Alex, and wonders if she's failed him. Neela discovers she's no longer Dubenko's favorite, and Gates has an unexpected, and unwelcome, visitor.

Luka treats a man with a failing heart, and later must make heartbreaking decisions concerning the man's Alzheimer's-stricken father. Language presents a challenge when Neela and Abby treat a good Samaritan. Meanwhile, Pratt tries to help Chaz make a new career choice, Gates has troubles with his own father, and Sam's got her hands full with a seminar on handling aggressive patients.