This is a great series for younger readers who want a bit of mystery and suspense in their books but aren't ready for something too long. There are four books in the series. BLue, Green, Red and Secret of the Painted House are others.
This book asks the reader to follow two characters living in two different time periods. Sound intriguing? I have 7, 8 and 9 year old girls coming back for more and more of these books. They are looking for something with a bit of suspense but aren't ready for anything too long.
When they're done with this series, you might want to try the Sherlock Files or possible Enola Holmes mysteries.
