"Obsidian mystery"--Spine.

"Kidwella Castle in northern Wales is rumored to be haunted by a deadly ghost-the Grim Widow, who allegedly drowns unsuspecting guests in the castle's moat. Not long after M. J. and her crew arrive at the castle to film their ghost-hunting cable TV show, Ghoul Getters, two new victims are added to the Widow's grisly roster. Fear ripples through the castle, especially when it's discovered that the victims may have had help into their watery graves from the land of the living. The local inspector suspects father-son serial killers, but M. J. thinks that theory is all wet. To catch the true culprit she will need to dive deep into the castle's past and bring some long buried secrets to the surface."--P. [4] of cover.