three P.M.
The crew alone remained upon their legs . It seemed like the climax to the storm . But another stage swiftly developed . It might have been somewhat after three P.M. when a shroud of darkness settled from the heavens , its substance foreign both to cloud and sea . It was thicker than before , and decidedly more musty . As black as night , but unrelated to all ordinary essences of darkness , it wrapped the stormy universe in Stygian folds with a suddenness strangely disquieting . The cataclysm followed almost instantly , as if from behind a concealing curtain .