With this episode, recurring actor Sharif Atkins becomes a regular in the role of med student Michael Gallant, while former regular Eriq La Salle makes a brief encore appearance as Peter Benton. Greene (Anthony Edwards) tries to keep the return of his brain tumor -- and his subsequent treatment -- a secret from his wife, Elizabeth (Alex Kingston), with disastrous consequences. Chen (Ming-Na) deals with a comatose patient who has somehow become pregnant. Abby (Maura Tierney) avoids her attacker, Brian (Matthew Settle), by briefly moving in with Kovac (Goran Visnjic). And a fistfight breaks out between two of the staffers in the ER admitting room. ~ Hal Erickson, Rovi