[s4e1] All That Glitters · Trusted & Verified

Takes a lead role in bridging the investigation between the veteran suspect and the broader trafficking ring.

The episode explores the "ridiculous chain of command" within elite circles and the moral exhaustion agents face when confronting institutionalized crime. Alternative Reference: The Curse of Oak Island [S4E1] All That Glitters

In this episode, the Lagina brothers conduct a massive second dig in the Money Pit and find potential evidence of a shipwreck in the swamp. Takes a lead role in bridging the investigation

Originally from FBI: Most Wanted , Crosby is central to this episode as he pursues a former comrade. which fits your specific S4E1 criteria.

Below is a formal summary of the Season 4 Premiere, which fits your specific S4E1 criteria.