The Jeroboam approached and "ranged abeam under the Pequod's lee, and lowered a boat that soon drew nigh". But Captain Mayhew let it be known that there was "a malignant epidemic" aboard his ship and, remaining in the boat, refused to come into direct contact with the Pequod's crew. With some difficulty, the rowers in Mayhew's boat were able to keep alongside the Pequod while some conversation was exchanged. It was then that Stubb recognized one of the rowers as the one he was told about "when the Pequod spoke the Town-Ho".
It seems that this "scaramouch" had been something of a prophet to a sect of Shakers [a celibate religious group], but -- inexplicably -- he took it into his head to go to Nantucket as a green-hand whaleman -- and was shipped aboard the Jeroboam. As soon as the ship was out of sight of land, he "announced himself as the archangel Gabriel and commanded Captain Mayhew to jump overboard". In so doing, he won over the superstitious, fearful crew immediately; he refused to work except when it pleased him to do so; and he threatened the ship and all hands to "unconditional perdition" should the captain try to get rid of him. The crew informed the captain that they would desert the ship if Gabriel were removed. And so Gabriel had the complete freedom of the ship -- and when the plague struck, he declared it was his doing, whereupon he got homage such as might be rendered to a god. "Such things may seem incredible, but the history of fanatics is replete with their own self-deception, and their measureless power in deceiving so many others."
"I fear not thy epidemic, man," said Ahab from the bulwarks [side railing], "come aboard." But Gabriel here interrupted: "Beware of the horrible plague!" At this, Captain Mayhew tried to shut Gabriel up -- but the boat lurched in the wind. "Hast thou seen the White Whale?" demanded Ahab. And Gabriel pipes up, Beware of his horrible tail! Captain Mayhew, furious, shouts, "I tell thee again, Gabriel, that --" But the boat lurched again.
Remarkably, Captain Mayhew was able to tell his tale of Moby Dick despite the riotous waves and the insolent interuptions from "God's Hero". It seems that Gabriel had forbidden the striking of the great White Whale, insisting that it was "the Shaker God incarnated" -- but Macey, the chief mate, had defied fate and managed to get a harpoon into Moby Dick. Gabriel ascended the main-royal mast-head and shouted prophecies of doom down on Macey's head. Sure enough, a flick of the whale's tail and Mate Macey went flying through the air, sinking down to Davey Jones. Gabriel claimed credit, Moby Dick cruised away, and the Jeroboam filled with nameless fright. From the tossing boat Gabriel bade Ahab to beware the blasphemer's fate.
It turns out that the Pequod's mail bag contained a letter from Macey's wife. In being transferred to Mayhew's boat, the letter fell into Gabriel's hands. The scaramouch impaled it on a knife and hurled it back to Ahab crying, "Nay, keep it thyself -- thou art soon going where Macey now lies." After that, many strange things were hinted among the Pequod's crew in reference to this wild affair.