Dr. Julian Mercer, played by the always brilliant Keanu Reeves, is the third person in a love triangle involving Harry Sanborn (Jack Nicholson) and Erica Jane Barry (Diane Keaton).
"Something's Gotta Give" is a romantic comedy starring Jack Nicholson and Diane Keaton from 2003. At the center of the action is Harry Sanborn, a womanizing music mogul who finally falls for a woman his age after he has a heart attack.
Erica Barry (Diane Keaton) falls in love with Harry Sanborn (Jack Nicholson) a swinging senior citizen who originally was dating her daughter. Their courtship is at the center of "Something's Gotta Give."