Sibling Rivalry

Plot:

When a champagne bomb is delivered to Constantine, he and Celeste (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 (Derrick Trumbly), following a severe cycling accident.