| Summary | Book Title |
| At home in another Caboose, the children unravel the mystery around a circus that long since out of the ring | |
| Summer vacation on a mysterious island lends itself to new mysteries and new family | |
| Living in a seaside home the Aldens, unravel the mystery of two lonely women | |
| A radioactive mine caused Benny and his friend to find themselves in another mystery | |
| Returning to eccentric Aunt Jane this double puzzle has it all - romance and a chase | |
| A return visit to Surprise Island leaves Benny spooked by an old house and the disappearance of a friend. | |
| After surviving a landslide, the Aldens discover a Native American secret | |
| Always curious, Benny helps capture a swindler in a small fishing village | |
| Impossible to just be a relaxing houseboat vacation, there is a blackmail mystery aboard. | |
| After the death of their parents the children take refuge in an abonded boxcar before being found by their Grandfather | |