S1, E13: Scrooge buys old Castle Strangeduck, intent upon turning it into the poshest hotel in the world! Complications arise when the castle appears to be haunted by the ghost of Dr. Ludwing von Strangeduck, himself! The strange goings-on turn out to be due not to Strangeduck's ghost, but to Wolfgang, Strangeduck's former assistant, who is trying to frighten off others so he can find Strangeduck's invisible paint formula.