His trademark was the red book in which he kept detailed designs and sketches. However, as Helen discovers in Norfolk where several of his designs are, the red book for his very first commission Catton Park is missing. She meets Gill Renouf, Chair of Friends of Catton Park, can she shed any light? And just how important were these red book to find out Helen goes to Sheringham Park, Repton's favourite work designed towards the end of his career and talks to Sally Bate, Vice Chair of Norfolk Garden Trust. Finally, onwards to Cromer, Northrepps where Helen meets Simon Gurney who has something very special to show Helen -the red book for Northrepps which Simon has been using to restore his Repton landscape.

So maybe with all this focus on Humphry Repton on his bicentenary year which the Garden Trust is leading, perhaps the mystery of the missing Catton Park red book might finally be solved.

The producer is Perminder Khatkar.