Who would expect to find deep beneath their feet an ice-making machine, a telephone exchange, a waterfall, two frozen turbots, and a Prime Minister's bedroom? This is the dark nether-world in which the Under London Expedition takes a light-hearted look at the strange, complex labyrinth of tunnels and sewers, railways and shelters, vaults, crypts and caves, which are as remote to the world above as the farthest reaches of Patagonia - and as full of surprises.