In Herman Melville's Moby Dick, what happens to Moby Dick at the end?

Herman Melville does not specify what happens to Moby Dick after the whale destroys the Pequod and all the whaling boats, killing everyone but the narrator Ishmael. Captain Ahab is caught in a harpoon line and is dragged down to his death by the whale. There seems no reason to think that Moby Dick would have died, although he might be burdened with harpoons and entangled in harpoon lines and might even be dragging Ahab with him for some time. However, the harpoons should work themselves loose eventually, and that would rid Moby Dick of the lines and of Captain Ahab. According to the e-notes Summary of the final chapters of the novel:

Ahab’s boat is the last one left. He once again throws his harpoon and makes fast to Moby Dick. The line runs afoul, and as Ahab stoops to clear it, the line catches him around the neck. He is silently pulled from the boat, down into the depths by Moby Dick.

In Herman Melville's Moby-Dick, what happens to Moby-Dick at the story's end?

Herman Melville’s Moby Dick concludes with a three-day chase for the legendary white whale.  Led by the relentless Captain Ahab, who lost ships and his leg to the monstrous whale, the chase is a revenge quest to slay the elusive creature who continuously torments Ahab.  As Ishmael states, “All that most maddens and torments, all that stirs up the lees of things; all truth with malice in it; all that cracks the sinews and cakes the brain; all the subtle demonisms of life and thought; all evil, to crazy Ahab, were visibly personified and made practically assailable in Moby Dick” (Melville 153).  Thus, the novel concludes with a maddened battle between Captain Ahab and Moby Dick that leads to total destruction. 

The final encounter occurs in the Pacific Ocean near the Equator after Ahab is informed of recent sightings of Moby Dick.  Ahab sails his ship, The Pequod, towards the whale and prepares his crew for battle, even anointing his harpoon with the blood of the three harpooners, Queequeg, Tashtego and Daggoo.  On the first day, Ahab senses the presence of the whale and orders his men to lower the harpooning boats.  Moby Dick surfaces and “the grand god revealed himself” (Melville 448).  The whale rams the side of Ahab’s boat and “shook the slight cedar as a mildly cruel cat her mouse” (Melville 449).  Ahab’s boat is broken into pieces and cast into the ocean with some of his other men.  The Pequod comes to their rescue and Moby Dick disappears. 

On the second day, Ahab spots Moby Dick again and three harpooning boats are dropped into the ocean.  The harpooners successfully stab Moby Dick, but the whale’s violent thrashing and immense strength destroys two of the boats.  As noted by Ishmael, when Moby Dick dives underwater, he “disappears into a boiling maelstrom” (Melville 456). Again, Moby Dick escapes, but not without taking Ahab’s ivory leg.  Ahab vows to kill the white whale, even if he must dive to the depths to get his revenge.  He states, “I’ll ten times girdle the unmeasured globe; yea and dive straight through it, but I’ll slay him yet!” (Melville 458).

Finally, on the third day of the chase, Moby Dick is spotted again, but he now is towing the dead Parsee behind him with a snagged harpoon line.  Ahab orders for the boats to be lowered and is able to hit Moby Dick in the side with his anointed harpoon, but the whale quickly retaliates and smashes into the bow of The Pequod, sinking the ship and drowning the men.  In one final act of desperation, Ahab tries to harpoon the whale, but his line catches around his neck and he is taken down to the depths with the whale.  Ahab and all of his men, except Ishmael, who clings to a floating coffin for safety, are killed in this final encounter, and the ship goes down in Moby Dick’s vortex and disappears without a trace: “And now, concentric circles seized the lone boat itself, and all its crew, and each floating oar, and every lance-pole, and spinning, animate and inanimate, all round” (Melville 468). 

Thus, at the conclusion of Moby Dick, the whale escapes after killing Captain Ahab and his crew and destroying The Pequod.