Infected with the Pox of LeChuck, McGillicutty had previously been attempting to convince the Merleader to hand over the three summoning artifacts and tell him the secret summoning words that would bring them the Legendary Sea Creatures to lead them to La Esponja Grande.
When he was unable to take them with words, his rage took over and he began a full scale assault on the Jerkbait Islands, surrounding them with a pirate ship blockade and causing extensive damage to Spinner Cay itself. In the meantime, he kidnapped the Merleader intending to force her to do what he wanted.
Trapped on the island were Elaine Marley, Guybrush Threepwood and the human LeChuck. Reginald Van Winslow had successfully escaped before the blockade was in place and waited for Threepwood to escape so that he could pick him up.
Marley devised a plan to distract the ship manned by Murkel Trenchfoot in her own ship, while Threepwood distracted Killick Hardtack using a cannon on the beach of Spoon Isle. While the two pirates were distracted, LeChuck was to use the raft to sail through the weak point board The Screaming Narwhal and go after McGillicutty's flagship to stop him and rescue the Merleader.
However, she entrusted Threepwood to pass this message on to LeChuck, who distrusting of his old foe, instead had him man the cannon on the beach while he (Threepwood) went after McGillicutty.
Once Threepwood had got clear of the blockade and attacked McGillicutty, the pirate ships dispersed having been driven off by Marley and LeChuck.
Threepwood was able to sink McGillicutty's ship and rescue the Merleader.