Unlike the other Weedle mice, The Stowaways love to go on adventures - even when it means getting close to humans! But when Rory and his Gran plan to rescue Grampa Stowaway, whom everyone else thinks is dead, the adventure may be far more dangerous than he has bargained for.

The Stowaways aren't like the other Weedle mice. They are inventive and curious, they go on adventures, and they are much too clever for their own good. In fact, everyone knows that Grampa Stowaway was killed in a trap on one of his adventures. So, who would want to associate with a family like that?

There's something else about the Stowaways. They keep secrets. Rory has made friends with a bird, their natural enemy; and his twin brother Morgan dreams of sailing away. But Gran has the biggest secret of all - and Rory has discovered what it is.

If Rory and Gran act on their suspicions, will they be heading for disaster? Or will it be the greatest Stowaway adventure of all?