Voyage to the Bottom of the Sea (1964)

S1E14 The Ghost of Moby Dick

Nelson welcomes an old friend onto the Seaview, who is eager to pursue research on the massive whale that had previously wrecked his ship, leaving him injured and causing the death of his son. However, it soon becomes clear that his true intentions are driven by a desire for revenge rather than genuine scientific inquiry. Crane grows increasingly worried that the Admiral is getting entangled in his friend's dangerous fixation.