It was summer and Primrose woke knowing that it was going to be a very special day. The sun was already warm and a light breeze stirred the leaves and branches of Brambly Hedge. It was a perfect day for an adventure.

Leaving the hedge behind, Dusty, Poppy, Primrose and Wilfred set off downstream in Dusty's boat the Periwinkle, on a journey that would take them all the way down to the sea. But it wasn't all plain sailing, and the mice had an important mission to fulfil before they could return to Brambly Hedge...