 Testing it on a strawberry, Dave Lister opts to test the two copies it makes, finding that one is succulent tasty while the other is filled with maggots.Kryten deduces that the device creates copies that appear identical but are different - one retains the best elements while the other retains the worst.When Lister opts to test the device in reversal mode, he inadvertently destroys the ship's science lab, damages Holly's voice unit and sets the ship's engine core into meltdown.