County is undergoing extensive renovations, and with Carter out of Africa but in trouble with Abby, a new med student (Parminder Nagra) comes between Chen and Pratt. Meanwhile, a mother's hidden ailment causes a tragic car accident; and a long-distance phone call leaves the staffers shaken and one doctor heading for the door. Chuck: Donal Logue. Chen: Ming-Na. Pratt: Mekhi Phifer.