Death Pits

From MTG Salvation Wiki

The Death Pits of Rath were a place filled with an oily black, semi-sentient substance separating the Furnaces of Rath from the Stronghold itself. During the Weatherlight's incursion into the Stronghold, the Death Pits were one of the many hurdles the crew had to surpass in order to reach their captain, Sisay. It is believed that the Death Pits were the result of many of Volrath's various failed experiments.