That was unusual. Pasha Bey had not, in a goodly number of years, seen anything fearsome enough to give him qualms. He was a hardened rogue, afraid of nothing. That is, he feared nothing until he saw the bronze man. One look at the big, metallic American scared Pasha Bey. There was something terrible about the giant Yankee. (from The Sargasso Ogre, by Lester Dent)
Doc Savage and company, on the ocean voyage back to New York with the treasure from their previous adventure, find themselves detoured into an ancient sea of mystery, surrounded by generations of its dangerous inhabitants.
Doc steals two of his associates back from the grim reaper, and takes on the murderous leader of a pirate gang who is nearly his physical match, dodging and staying one step ahead of him on his home turf, the Sargasso Sea.
For much of the story after prospects start looking impossibly grim, Doc has to go it alone without the help of his men, who end up captives with their fellow passengers. Along the way, his personal rule against taking human life gets sorely tested, though it appears throughout the story that his adversaries have more to fear from their own leader than they do Doc Savage. Nevertheless, it's all Doc can do to keep himself alive while the villain positions his men around him in a tighter noose, keeping up the suspense all the way to the ending.