Lister’s despair at life after humanity lifts when Kryten, having discovered some mutated development fluid, creates photographs that literally revisit the past. With no regard for the laws of causality, Lister looks to exploit the discovery for his own ends, talking his teenaged self into inventing the “Tension Sheet”, a billion-selling sheet of painted bubble-wrap. Suddenly alone on Red Dwarf, Rimmer is left with little choice but to “save” his crewmate from a life of luxury. (thetvdb.com)