Detective Comics, Vol. 1

At a charity art viewing event put on by Bruce Wayne, Kerry Rollo displays a 50,000 year old "power bone" from Australia; an Australian aboriginal named Umbaluru finds 3 men who stole the power bone, who said Kerry Rollo had the bone before being killed by Umbaluru; after Umbaluru left, Batman arrives and sees aboriginal markings on the corpses, and wanted to check with Rollo to see if it was coincidental; Batman arrives too late - Umbaluru had already found Rollo; Rollo fell to his death by Umbaluru, and Umbaluru escaped.