The actor and presenter embarks on a 200-mile journey from source to sea to discover what makes the Thames one of the greatest rivers in the world. He begins by tracking down the source of the waterway, as it emerges from the ground as a pure spring in a Gloucestershire field.
The actor and presenter follows the river as it winds its way through the Thames valley, stopping off at Henley-on-Thames, and then on towards the palace at Hampton Court. In the village of Clifton Hampden, he tries his hand at sailing a skiff, and later visits Thames Water's most advanced sewage plant. In Henley-on-Thames, Tony attempts to cox a crew from the elite Leander Rowing Club, Britain's most successful sporting team who boast 124 Olympic medals, and at Hampton Court Palace, he boards the gold-encrusted Glorianna, the Queen's Royal Barge that led 1,000 boats down the Thames during Her Majesty's diamond jubilee.
Reaching central London, the actor and presenter boards an industrial working ship on the Thames, learning it is a route not without risks as ships must squeeze under bridges at high tide and avoid running aground at low tide. At the Chelsea embankment, Tony explores the Physic Gardens where early botanical remedies were created from exotic plants brought in by river from all over the world. On the south bank, he goes mudlarking, scouring the shore at low tide for objects discarded by revellers past, before getting a bird's-eye-view of the river from the Shard. Tony's final stop is Tower Bridge.
The actor visits the East End of London, going on patrol with the Metropolitan Police Marine Unit and attending an emergency call-out to an unexploded bomb. At Billingsgate fish market, Tony reflects on his teenage years working on the docks, before ending his journey in the Thames Estuary. He discovers that the river is now cleaner than it has been for 500 years, which is encouraging seals to once again claim the waters as their home.
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.
Tony goes behind the scenes at the iconic Cutty Sark in Greenwich, meeting with the passionate team who care for this historical tourist attraction. Later, Tony visits a metal recycling yard on the banks of the river, before heading out of London to the Hoo peninsula in Kent, where he discovers a rich history of military defence in one small fort.
Tony watches a tunneling machine being transported up the river into central London, and discovers plans to build a new tunnel under the Thames to take pressure off the crossing at Dartford. He also makes a late-night visit to New Covent Garden Market, and meets a Paralympian in training at Marlow Rowing Club.
The actor and presenter starts his journey heading up the estuary to Southend Pier, where as a young man he'd drive to with friends. But the pier was original conceived in Victorian times to attract day-trippers from London - and tempt them away from nearby Margate. It's now the longest pleasure pier in the world and, as Tony discovers when he lends a hand replacing a girder, it requires a lot of maintenance.
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.
London City Airport, right in the middle of the capital, is built on an island in the Thames itself, creating unique hurdles for the people who work there. Tony Robinson finds out more about those challenges as he meets a pilot, joins the airfield operations team, and takes part in a drill with the airport's firefighters.
