American Mystery (Don't Doubt the Rainbow 3)

It is the school summer holiday, three months after Edie Marble faced off with the eco-terrorists. Grandpa David is unwell and has asked his son, Edie's dad, to bring the family to Canada to see him - possibly for the last time - although he doesn't mention that he's already secretly reached out to Edie. In Toronto, Edie uncovers a dark secret from her family's past that has been buried and seemingly forgotten about, but when Grandpa David starts receiving strange messages from an unknown number