The Pequod comes in contact with the Rachel, a boat that reports, through its Captain Gardiner, that they have seen Moby Dick, and that, the day before, they lowered boats to capture some whales and saw Moby Dick alongside. A last boat, containing the captain’s young son, was sent to battle Moby Dick, and though it hooked him, the boat was dragged some distance to the horizon and lost. Gardiner and the rest of the crew of the Rachel did all they could to find the boat and the captain’s son, but saw nothing.
In marked contrast to Ahab’s emotions regarding his own family—with whom he has made no attempt to communicate throughout the course of the novel—Gardiner feels it is absolutely necessary to do everything he can to locate his son. Indeed, he believes that a fellow man will recognize this emergency and do all he can to help find the boy.
Gardiner asks if Ahab will join with him and his crew in seeking out his lost whale boat, in the hopes of finding the abandoned boy. But Ahab tells Gardiner he will not do it, despite Gardiner’s protestations that Ahab himself has a small child. Ahab claims he is already losing time in talking with Gardiner rather than searching for Moby Dick. Gardiner, horrified, boards his own ship and sails away, and Ishmael comments that the Rachel, like the Biblical character Rachel, appears to be in mourning for its “lost child,” the captain’s son.
But, of course, Gardiner does not understand the overwhelming monomania of Ahab’s quest. Gardiner's shock at Ahab’s heartlessness is a signal of Ahab's lost humanity. He puts his quest for the whale above the life of a boy, or even above the hope that the boy might be alive. In the Bible, Rachel is the mother of Joseph, whom his brother's betray and send into slavery in Egypt. So she loses and mourns for her son.