Len Skeggs was a housebreaker and a thief.
Len tried to break into a house that was shabby and a little secluded. His professional experience told him owners of houses like this tended to keep their money and valuables in their homes. He had great difficulty breaking into the house; none of his tools worked. When he heard a strange noise in the house, he retreated a bit. He saw two hooded, robed figures enter the house and followed them.
The three went to the cellar, and Len watched as the Fifth Doctor and Peri entered the cellar and were attacked by the two figures. He then saw the owner of the house kill the two figures and leave with a valuable-looking gem. Len wanted the gem, and hit the man with his jemmy. The man wasn't flesh, but metal, surprising Len, but he recovered enough to grab the gem in its casing and run off with it. Once away, he destroyed the casing to get the gem. However, when he picked it up, it burned his hand with cold, and the heat of his hand caused it to turn into gas, as it was ammonia and methane ice. The gas killed Len. (PROSE: Hot Ice)