In the action-packed fourth season of Historys mega-hit reality series, The Curse of Oak Island, Brothers Rick and Marty Lagina along with their team pull out all the stops for the biggest and most expensive operation ever in an attempt to solve the 221-year-old treasure mystery. Utilizing 400 tons of heavy equipment they dig four massive shafts in the Money Pit area leading to incredible finds that include golden artifacts, important historical clues and even stunning evidence of the legendary treasure vault. The brothers also make other compelling finds on property once owned by a former American slave turned wealthy landowner and in the mysterious triangle-shaped swamp revealing that Rick, Marty and their partners may be closer than ever to unlocking the secrets that have remained hidden for more than two centuries and cost six men their lives.