Temple of the Deep Ones
"Temple of the Deep Ones" is the lair of a group of deep ones and their god, suitable for four or five 7th-level characters. This adventure can be finished in one session.
Ship captains report that a mysterious island has surfaced in the middle of a heavily trafficked trade route. Worse, ships that venture too close to the island are assaulted by a terrible creature and its servants. The island is disrupting trade throughout this part of the world, and several ships have already been lost.
Unbeknownst to those that know of the place, the island rises at the will of Shar-Ngolyeth, a long-lost deity also known as That Which Lurks Beneath the Waves. The island is populated by a cult of deep ones and the beasts they have subjugated in the name of their dark god. The creature responsible for sinking ships is an aspect of Shar-Ngolyeth, a kraken. It is not meant for combat encounters; it's largely a plot device in this encounter.