Revenants ( short story ) Revenants was the eighth short story in the Short Trips anthology " Short Trips and Side Steps " . It was written by Peter Anghelides . It featured a future Doctor . Summary . The Doctor and Guin materialise on the Schrödinger Institute , a deep - space research station . The Doctor expects to see an old acquaintance , Tasdevin , who is working on a perpetual - motion machine . They wander the station for a while , and it seems to be deserted . They make their way to the huge central core housing the accelerator and laboratory equipment . In the lab , the Doctor types at a keyboard , but many of the keys are stuck . Guin tries to lift some papers from a desk , but can only lift a few . She notices that an orange cup on the desk cannot be moved . Suddenly , Tasdevin storms into the room . He throws some papers on the desk and starts typing on the keyboard . Groote enters after him , carrying an orange cup . Guin tries to apologise for their presence , but Groote passes right through her . She and Tasdevin start arguing , with Groote trying to convince Tasdevin not to continue with his experiment . He ignores her , and takes a box - like object with wires and connectors in it . He puts it in an open space in a standing obelisk . He pushes a button and turns to Groote , holding a knife . The lights flicker . Three men , van Ruysbroeck , Fauler and Suso , burst into the room , yelling for Tasdevin to stop . Tasdevin says , " Too late " , and the obelisk explodes in a brilliant light . Guin and the Doctor find themselves in the same room , alone . Events play out just as they did before , with the obelisk again exploding . Once again the Doctor and Guin are alone . The Doctor theorises that Tasdevin ' s experiment has caused a temporal echo , and that the others are just echoes of the real people . Tasdevin and Groote enter as before , and the Doctor pushes at the orange cup after Groote has set it down . Guin notices , and when the three scientists burst in , she goes out through the door . When the next flash hits , she is in the corridor . Guin wanders the station until she finds the canteen . The three scientists are on their way out . Guin enters the canteen and works at a computer until the next flash hits . The five scientists are now in the canteen . Fauler tries to convince Tasdevin to stop his experiments . Tasdevin leaves in anger when he realises that Fauler has been reading his personal diary . Groote leaves soon after . The remaining three discuss the situation , and Guin learns that all three men are from Galextricity Corp , which provides energy for Tasdevin ' s homeworld . Tasdevin ' s research is a threat to Galextricity . The three men leave , the lights flash , and another cycle begins . Guin escapes the canteen by following Groote . She rejoins the Doctor , who has been looking at Tasdevin ' s notes . Tasdevin is trying to stabilise a portion of space - time , hoping it will constantly recycle and he will never age . The lights flash again . As the next cycle begins , Guin casually mentions how they cannot touch anything that one of the scientists will use until the scientist is done with it . The Doctor realises the solution : he will switch the wiring in the obelisk at the last minute , after Tasdevin has touched it . When the time arrives , however , he can ' t reach the wires , so Guin has to support him on her shoulders . After he switches the wires , Tasdevin once again says , " Too late " , but this time , the five scientists fade away . The Doctor says that once they leave the station , it too will fade away . References . " to be added " Continuity . " to be added "