The heroes storm the Temple of R’gu, the God From The Stars, to steal the Ruby of the Winged Master
Enter the Kingdom of Frog King in search of Treasure. What deal will you have to strike to get out alive?
Temple of some malign being invites you warmly and offers help (curing,needed spell etc) for some minor sacrifice . Sacrifices must be everytime bigger to work - up to living inteligent creatures. Maybe you pay some other price,too...