The twins family arrives in Portugal only to find that their host for them has disappeared and a package left for them has been stolen. The twins track down one clue after another.

The Bobbsey twins' dog, Snap, finds a packet of money and the twins must find the owner.

Bobbsey Twins series.

While vacationing in Bermuda, the four Bobbsey twins become involved with a pair of thieves trying to steal valuable artifacts from the local museum.

A memorable visit to the country involves the entire Bobbsey family in a bewildering mystery. Adolescence.

While on a trip to New York City, the Bobbsey twins meet Jack Whipple, a man who works on an estate outside their hometown. The twins help the old man to find his long-lost brother and sister, as well as to catch the man who had robbed the estate and then cast the blame on Whipple.