The Grid
From Tardis Wiki, the free Doctor Who reference
The Grid was a set of Nanobots that wanted to take control the world after the Third Doctor said he didn't have claim to it. They used electrical energy from flesh as a battery. They were trapped in a metal box and placed in the UNIT Vault under St. Pancras. (AUDIO: Kaleidoscope [+]Loading...["Kaleidoscope (audio story)"])