In a 19th-century whaling harbor, the peg-legged captain of the Komquot is obsessed with catching the great white whale, Dicky Moe, to the point of drawing cuts of meat on Dicky Moe's picture, then eating the paper out of insanity. His obsession frightens his crew so badly that they all desert the ship in fear, angering the captain for their cowardly behavior. Shortly afterward, the captain finds Tom searching for food in the harbor, knocks him out and takes him aboard. Tom thinks at first that he is going on a cruise, and sets himself up with a chaise longue and a drink, but the captain almost immediately slams him out of it and forces him to work scrubbing the deck. As Tom works, he sees Jerry set up a beach chair outside his hole. He grabs Jerry and scrubs away all his colors, leaving the mouse visible only as an outline. Jerry returns to his hole to get his colors back, switches Tom's water bucket for one filled with tar and tricks him into scrubbing the deck with it. Tom chases Jerry across the deck, only to get the entire bucket of tar dumped on him from head to toe; he briefly poses as the captain's shadow to avoid being spotted and attacked, then gets wiped clean when the captain slams a door open, smashing him into the wall. Next Tom spots Jerry lounging in the rigging; he goes mad and begins to shake him loose by undoing the knots. One of the heavy blocks swings loose and knocks Tom into a barrel of harpoons, leaving his nose stuck in one of them as the captain grabs it. Enraged, the captain pulls every which way and finally throws the harpoon for target practice, finally dislodging Tom. Jerry tricks Tom into stabbing his own tail with the harpoon thinking it is a white mouse. Tom sets a trap with a dangling anvil; Jerry comes, but spots the trap and switches Tom's bait with a fish to mess with him. Tom dives for the fish, but the anvil drops on his own head, sending Tom crashing through the ship's hull and into the ocean. With the help of a rope thrown by Jerry, Tom climbs back on board just as the captain sights Dicky Moe and fires a harpoon gun at him, and the rope flies up. Tom realizes too late that he is holding the free end of the harpoon's rope and therefore gets yanked off the ship. As the whale swims off with Tom tied to him by the rope, weakly screaming "Help", the captain shouts for him to "COME BACK WITH MY WHALE!!!" In his hole, Jerry settles down with a book and reads it, scoffing at the situation.
