Messages from the future, precognition, the Butterfly Effect, the Grandfather Paradox, time loops, multiverses, wormholes... There seems no end to the variations on the time travelling theme. Yet filmmakers were slow to recognise its dramatic potential. Despite several screen versions of Mark Twain’s novel "A Connecticut Yankee in King Arthur’s Court" (1889) and H.G. Well's novella "The Time Machine" (1895), and time travel being adopted as a recurring device in 60s TV shows such as "The Twilight Zone" and "Star Trek", it remained a marginal phenomenon on the big screen, chiefly confined to experimental or arthouse films ("La Jetée", "Je t'aime, je t'aime", "Idaho Transfer"). But the floodgates finally opened in the 80s blockbuster era with "The Terminator" (1984) and "Back to the Future" (1985), mainstream entertainment that hit the sweet spot between science and fiction. Henceforth, time travel, bolstered by increasingly sophisticated special effects, would be a familiar element in Hollywood's SF arsenal. Offscreen serves up not just crowd-pleasers such as "Bill and Ted's Excellent Adventure", "Looper" and "Interstellar", but some of the lesser known and alternative examples of the genre, from rip-roaring B-movies such as "Trancers" (1984) to brain-scrambling cult favorites such as "Timecrimes" (2007) and "Triangle" (2009).