Episode Title: SIBLING RIVALRY
Summary: When a champagne bomb is delivered to Constantine, he and Celeste (guest star Jennifer Beals) go on high alert to determine who wants him dead. Meanwhile, Nate turns to Grace after he accidentally jeopardizes a mobster's valuable racehorse. Back at Roosevelt Medical Center, Grace is tapped to treat Brett's estranged brother, Jack Hanson (guest star Derrick Trumbly), following a severe cycling accident.
Airdate: December 31, 2012