When the squad’s rig breaks down in the field, Casey reunites with his old friend and colleague Jason Kannell from Squad 6. Dawson and Brett serve their time in retraining….

The unit scrambles to search for one of their own who is in grave danger.

Sam treats an abused, pregnant teen. Dr. Carter introduces African girlfriend Makemba to wintertime. ER chaos shocks a risk-assessment expert. Dr. Pratt and Abby restrain a man who has tuberculosis.

Michael finds out a storeroom fundamental to his escape plans has been converted into a break room. Veronica and Nick are being threatened.