After experiencing a strange time phenomenon, the crew must venture on board a starship from the 24th century to stop them from crashing into an oncoming gas moon, only to be hindered by its unorthodox anti-criticism law.
After the crew claim a moon rich in Helium-7 for the JMC (an exercise orchestrated mainly by Rimmer), they are forced to leave sooner than anticipated because an incoming solar storm is detected.
On the way back to Red Dwarf onboard Starbug, the crew experience a timewave, which Kryten explains is the aftereffect of an imploding black hole, and that whoever falls victim to one risks the chance of being washed-up into an inhabitable corner of deep space.
They decide to board it to stop the collision, though their research tells them that the ship, which is from 24th-century Earth, has laws which prohibit criticism, so requiring the Red Dwarf crew to moderate their behaviour.
After a nearly-successful attempt at escape by the Red Dwarf crew, they sway the head policeman against the anti-criticism law, but Ziggy returns and orders that they be "drained" of their critical behavior.