The documentary series returns with an investigation into the phenomenon of lying.
The programme tells the story of science's attempts to banish the lie, and asks what life would be like if the honesty police got their way.
See today's choices.
(Stereo) (Subtitled)
Booklet: send a cheque for £3.00, payable to BBC Education, to: Horizon Liar, [address removed]. Please allow 28 days for delivery.
See Polly Toynbee: page 17