Quest for King's Underpants

You knows; the King's life is not so easy. Especially if he lost his favorite underpants. King Deridin has lost his precious underpants and he has entrusted you to find again them. But this is the easy part. The harder one will be to escape from the undergrounds. Will you be you able to return to King Deridin with his precious underpants and gets the regal reward?