
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.
In the second episode, Tony explores the river's role as a vital trade artery connecting the country to the outside world, going behind the scenes at London Gateway, the newest and largest container port on the Thames. Later, he visits Whitstable, famous for its oysters that come from the Thames estuary.