They wait for low tide to visit Sambo's Grave, a memorial to a black slave in the windswept marshes at the mouth of the River Lune in Lancashire and use his story to explore the North West's ties with the slave trade.
Rum, timber and tobacco are all associated with the Cumbrian town of Whitehaven and all have roots in the slave trade.
We try to unravel the tangle of connections: from the burial of George Washington's grandmother, Mildred Gale, with her black slave to the creation of the Beilby goblet commemorating a famous slave ship, King George.
Westminster Hall was the venue for one of the slave trade's most significant heavyweight contests in the eighteenth century, which resulted in slavery being effectively banned in England.
In the red corner, one of the unsung heroes of abolition, Granville Sharp, and in the blue corner for the establishment and the status quo, Lord Chief Justice Mansfield.
A memorial to a four-year-old girl at a Cambridgeshire church provides a clue to the life of the leading black abolitionist, Olaudah Equiano.
We explore his links with the girl and consider how their two lives and his great book, The Interesting Narrative, influenced attitudes in 18th-century Britain and promoted the struggle against slavery.