*Signed Bookplate*

Third grader Harriet is convinced that she’s in for a terrible, horrible, no good, very bad summer.

Her mother is having a difficult pregnancy, so Harriet is getting shipped off for the summer to stay with her grandmother who runs a bed-and-breakfast on Marble Island. She’s always loved short visits to the tranquil island with her parents, but spending two whole months there without them means change, and Harriet does not like change. She especially doesn’t like the idea of getting a new sibling. Fortunately, she’s got her beloved cat Matzo Ball to keep her company.

Sure, Marble Island is great. And it's impossible not to love Moneypenny, Nanu’s old basset hound. But Harriet still doesn’t like the fact that Dad made such a big decision without even asking her.

As Harriet spends more time on Marble Island, however, she discovers that it's full of surprises - surprises like an ornate key hidden in her grandma's shed. Suddenly, there’s a mystery to be solved. A mystery that seems to involve her dad’s childhood on the island and Miss Marble, the witty centenarian who is the island’s namesake. 

Maybe a bit of change isn't so bad after all. Maybe sometimes change can even be exciting.