Perseus' robot, a Household Assistance Device, was an entry in a contest sponsored by the president of London. It was the favourite to win.
When the Seventh Doctor and Chris Cwej questioned it, they could detect nothing suspicious about it. The Doctor provoked it to what Chris thought was anger.
The robot lost the contest when a girl brought in a superior android, which disabled the AI blockers on all of Perseus' robots. (PROSE: Anteus)