In this episode, Tony travels as far as the Estuary in the East and Waterhay in the West.

The actor and presenter starts the latest leg of his journey in Beckton. There he discovers how a new super-sewer is being built to help stop overflow from London's existing system ending up in the Thames. After a hair-rising cage ride down into the tunnel, Tony Robinson meets the engineer in charge of the project who explains how it will work.

The actor and presenter starts his journey in Richmond upon Thames, at Hampton Court Palace. This 1,000-room residence was King Henry VIII's favourite. Tony begins his tour by the Thames right where the loos would have been. It's also where the royals would have arrived by barge, and where merchants from as far away as Venice would have sold their fancy fabrics.