Rick and Marty Lagina along with their team make an incredible discovery in the waters surrounding Oak Island.

It's one step forward and two steps back for Josh and Bill as they near the completion of their bunker. Meanwhile, Jeff, Mark and Lance are $6000 in the hole after losing a batch of mash before starting work on their Highland Scotch.

A 1990s-theme prom is thrown for Phoebe when she gets her GED. Also, Abby goes on a second date with Dr. Harris, and Jo's former husband visits Los Angeles to spend time with his daughter.

On Ceres, Miller identifies the dead "Nightbandit31" as Bizi Betiko, a data broker with an implanted, encrypted memory storage device, only to discover the real Betiko is still alive. In the asteroid belt, the Donnager's pursuers reveal themselves as six ships of the type that had attacked the Canterbury, and begin firing torpedoes. Unexpectedly at a technological disadvantage, the Martian ship takes heavy damage, and Shed Garvey is killed by a railgun shot. As the Donnager is being boarded, the surviving Canterbury crew are evacuated on the Martian captain's orders, narrowly escaping aboard a corvette from Donnager's bay immediately before the Donnager self-destructs to avoid capture. Far from the battle, at Tycho Station, where a massive generation ship, the Nauvoo, is being built on behalf of the Mormon Church, station manager, and leader of the OPA, Fred Johnson turns the Nauvoo's sensors towards the battle.