Susannah and the Blue House Mystery — Patricia Elmore

Someone is watching...

Susannah Higgins and her friend Lucy are amateur detectives. They haven't had much business lately, at least not until Juliet Travis's grandfather disappeared.

Juliet's grandfather had lived in the Blue House, a scary , junk-filled mansion that gives Lucy the creeps. The answer to the mystery must be hidden somewhere in the Blue House's dark room. But where?

Then the girls discover that they aren't the only ones searching around the old mansion--and that someone will do anything to find the Blue House's secret--even murder.