After the funeral of his old partner, Danny, Sipowicz returns to the squad room and is abruptly teamed with his new partner, John Clark. Clark's father, John Clark, Sr. — Sipowicz's old nemesis at another precinct — butts heads with both Sipowicz and Clark Jr., when he interferes with their first case together, the mysterious stabbing death of a wealthy woman. Meanwhile, McDowell and Jones discover a vintage '56 Les Paul guitar is a key piece of evidence in the death of a young, struggling musician, and leads to the victim's own jealous roommate.The tension between Clark, Jr. and his father rises when Clark, Sr. crashes the 15th's toast to Danny.