Al Mamoon's Sheikh of Spice is suffering from a severe lack of enthusiasm.
This errand is available to complete after defeating Rusty's Nightmare.
Head over to Swift Solutions, where a new blue dot has appeared on your map. This is the Sheikh you heard of, but he's brokenhearted and needs help. First, stop at Rashaad's stand and talk to the woman just below it; she has some extra enthusiasm, so be sure to grab it with Take Heart. (Or, if you had already gotten her enthusiasm for a previous errand, you'll have to backtrack to Ding Dong Dell for it.)
Head back to the Sheikh, then give him the enthusiasm with Give Heart to return him to normal.