The Thirteenth Skull (Alfred Kropp 3)

Alfred Kropp lost—then found—the legendary sword Excalibur. Then he defeated King Paimon, arguably the nastiest of demons ever to roam the earth. What could possibly be in store for him now? Plenty. Not only is a dangerous new enemy tracking Alfred’s every move, even the people who have sworn to protect him no longer seem trustworthy. Who, or what, is "Sofia," and is there a connection between Sofia and the mysterious Thirteen Skull? The reluctant hero who has always narrowly avoided death may not be getting out of this adventure alive.