This curious time-travel novella is a gracefully told lesson about accepting fate-or, as better suits this medieval Arabian setting, the will of Allah. A Baghdad merchant discovers an alchemical device that can send a traveler back in time 20 years. Despite the alchemist's warning that "what is made cannot be unmade," and three illustrative tales about others' attempts to alter the past, the merchant is determined to return to an earlier time to save his long-dead wife