The story presents itself as a found “letter in a bottle” manuscript written by a German submarine captain who just sank a British ship during WW1. A member of the German crew removes a mysterious amulet from the pocket of a dead enemy seaman, and things begin to get weird.
The German crew begins experiencing mass nightmares, babbling, and visions of floating corpses in the sea. Things get worse for the cursed crew throughout the story as insanity leads to mutiny and murder.
Eventually, the U-Boat settles upon the bottom of the sea where there is a great temple on a large campus recalling tales of the underwater City of Atlantis. Lovecraft does a great job of creating a spooky atmosphere as our unreliable narrator explores the city and slips deeper into madness.
While not much actually happens in the story, it’s all about the vibe. Lovecraft was a master of creeping dread caused by circumstances and forces beyond our control. Taken in that context, “The Temple” is a worthy, short read.