In this series there are 4 children whose parents die so they lived in a boxcar instead of going to live with their grandfather because they feared he was mean. When the children do go to live with him they find to the contrary. In this book they are visiting their grandfather's college for a reunion. They are intrigued by the watch tower, where the mystery begins. The children are very close and their relationship with their grandfather is more like a father. A great series for young sleuths because of the many historical facts brought into the series.

Curriculum connection: Writing: Students could write a different ending to the book. Another writing could be to write their own mystery.

While visiting Goldwin University with their grandfather, the children find a mystery right in the clock tower.