BBCIts easy to see why Steven Moffat claims to loathe the internet. Its not just the criticism; that all-too-familiar swarm of mindless complaints that accompany pretty much every TV show, its that websites and wikis alike have given the audience an infinite capacity to catalogue, compare and contrast absolutely everything against absolutely everything else. Writers cant cheat, they can only choose whether or not they give a damn about the consequences. Theres an amusing nod to this newfound omniscience in the first Doctor Who Programme Guide, released in the early 80s; producer Barry Letts explains that Atlantis was destroyed three times during the shows early run. With TV being produced as fire-and-forget broadcasting, such little note was taken of what had gone before that each new team believed they were the first to visit the underwater city. Its baffling to think that nobody thought to jot anything down, but given the shows budget it was probably a choice between a Dalek and a new pencil. Fifty years later, though, theres really no excuse. When most stories are broken by teams of storytellers early in the production run, you cant even blame one writers pop-culture ignorance when they churn out a rehashed sci-fi idea that has you fumbling for next episode on Netflix. Its not that these plots are necessarily bad, but that the concepts and themes have been covered countless times before. In an on-demand world, we dont need the televisual equivalent of frozen leftovers. Leaving aside common plots that still have surprises to offer the audience (like time travel) or act as vehicles for character growth and exploration (like, er, time travel), here are ten worn out sci-fi stories whose sell-by date has most definitely passed: