Enter Geo. Find the bar area and talk to Niccolo. Have him join your party.
Enter the Ulkan Mines and go into Watts' Workshop. Exit and re-enter the Workshop. Watts will ask for that Gator Skin that I told you to keep. Go back with a Gator Skin and give it to him. If you don't have one, go to the Inn in Domina and talk to Miss Yuka. Re-enter the Workshop to end the Event.
Upon Completion: Return home, talk to Lil' Cactus, go downstairs (watch him write the Event on the leaf), and go back upstairs to save your game before continuing.