Scorched Rot and Rising Tides

The sewer tunnel stretched into endless darkness, and the water around us made it hard to breathe, as the filth flowed into our lungs, it was laced with filth and decay. The air was damp and choked with rot, a mixture of stagnant waste and something far worse—the scent of long-dead things that had never been given peace.

The blasted dead things were rising from the grave to attack us.

The creatures didn't lurch forward with the awkward, mindless movements of typical undead. They moved deliberately, with an unnatural fluidity, their waterlogged bodies swaying with the current as they inched closer. We needed to prepare before we were hit by a full-on horde of this drowned undead. 

One of them, its jaw slack and hanging too far open, lifted an unnaturally long arm and pressed its fingers to the surface of the water as it shifted about and tried to cling to us.