The Chamber.

"The Chamber" by Will Dean is a gripping and tense murder mystery set in an underwater hyperbaric chamber. The story follows Ellen Brooke, a female saturation diver, and her five male colleagues who are hired by an oil company to conduct maintenance work at the bottom of the North Sea. As they live and work in the pressurized chamber, one of the divers is found dead, causing trust among the group to fracture. When a second member dies, suspicions arise that one of them may be killing the others for the money. Will Dean skillfully builds suspense and offers a fresh take on the closed-circle murder mystery genre. [Extracted from the article]