In 1839, twelve-year-old Matthew's job as assistant to the phrenologist Dr. Cornwall takes him up and down the Eastern Seaboard and to Europe, as they rob graves and try to find out who is following them and why.

It is said that the Sahara Desert swallows the past. For Matthew Morrissey and his mentor, the eminent phrenologist Dr. Asa B. Cornwall, there's also the danger of its swallowing their present. In their search for the skull of Alexander the Great, Matthew and Dr. ABC journey across the Great Sand Sea in a camel caravan unaware of the perils-both human and otherworldly-that await them. Overtaken by slave traders, Matthew and the doctor must call upon all of their knowledge and wit to save themselves and some unfortunate others from disaster.