A Bermejo painting is the subject of Episode 8!
This is called Saint Michael Triumphant over the Devil. It was painted by one Bartolomé Bermejo in 1468.
If you look really closely, you'll see a really scary devil character at the bottom with a big grinning smile. It was probably the central panel of an altarpiece which was in the church of San Miguel (Saint Michael) in Tous, near Valencia.

The Great Fire Trail: a free Time Hunters history walk around the City of London
1:02:38

Marina Ventura and The Micro-Gridders: Your Go... Designing A Grid of the Future
04:40

Marina Ventura and The Micro-Gridders: Energy Guzzlers
05:27