Liverpool Sound and Vision Rating 9/10

Cast: Gareth Thomas, Paul Darrow, Sally Knyvette, Michael Keating, Jan Chappell, Alistair Lock, Brian Croucher, Bethan Walker.

Nothing quite makes Science Fiction more entertaining than when the cast of your favourite programme have been set a problem which drives at the very psyche, the paranoia of the mind and the suspicion in those that you would normally defend with your life. It has been done so many times on screen and the tension it creates can be one of palpable enjoyment and dread that it might spill over too far. It is about the timing of the paranoia and suspicion and knowing when to pull back, leaving just the trickle of distrust seeping through after all is seemingly resolved.