Off the German Baltic coast, the salvage vessel BT2 anchors above the wreck of the fishing cutter Friedrich Engels, 17 meters down, where abandoned fishing nets have snagged on the hull and kept killing marine life long after the boats that lost them are gone. The Baltic Sea Divers team, helmet divers Yan and Eric among them, drop in on fixed bottom-time limits to cut and haul the tangled netting free, working through poor visibility, unstable wreck structure, and gear that fails at the worst moments. Biologist Lena Platt works alongside them, explaining what these so-called ghost nets do to fish, seals, and seabirds over years of drifting and snagging, and why removing them matters more than it looks from the surface. The film stays close to the physical work itself, showing the topside support, the surface-supplied helmet rigs, and the slow, exhausting process of freeing a wreck one net at a time rather than dramatizing the science. It is a straightforward account of unglamorous, useful labor at the bottom of the sea.