Predestination paradox A predestination paradox , or time loop , was a phenomenon in which an event of time travel could become part of events which had already occurred , and could even lead to the initial event of time travel in the first place . Examples . In 2268 , after having traveled back in time from 2373 , Doctor Julian Bashir speculated that the events in which he was participating constituted a predestination paradox when he met crewmember Lieutenant . Realizing that his great - grandmother ' s name was , and that nobody ever met his great - grandfather , Bashir began to suspect that he was destined to fall in love with Watley and become his own ancestor . Bashir ' s suspicions were later proven incorrect , however , in that he did not pursue a relationship with her , a decision which had no effect on the timeline . Agents Dulmur and Lucsly of the Department of Temporal Investigations , who were sent to investigate the incident , professed to hate predestination paradoxes and were relieved to find out that the incident was not one of them . ( ) In 1968 , the crew of the " Enterprise " , who had traveled back in time from 2268 to perform historical research , encountered a Human named Gary Seven , who was attempting to sabotage a nuclear warhead platform . Fearing that Seven was an alien from the future attempting to manipulate the timeline , the " Enterprise " crew attempted to stop him , but Seven was eventually able to convince them that he was indigenous to the 20th century , and that he was in the employ of a benevolent race of aliens attempting to protect Earth . Later , upon checking their historical records , Commander Spock discovered that the crew of the " Enterprise " was , in fact , always a part of this series of events , and that , by interfering , they were simply fulfilling their role in history . ( ) In 1986 , needing money after travelling back in time from the year 2286 , James Kirk sold a pair of glasses which had been given to him by Leonard McCoy as a birthday gift . When Spock expressed his surprise at Kirk ' s actions , Kirk asserted his belief that they would wind up in his possession again . ( ) On several occasions Captain Jean - Luc Picard attempted to prevent a predestination paradox from forming by ordering the to stay on its current course , fearing that changing course to avoid a time loop may be the very thing that got the ship stuck in the loop in the first place . ( ) In another predestination paradox , two time - traveling Vorgon thieves from the 27th century arrived in 2366 to obtain the Tox Uthat from Captain Picard , who was known to have discovered and destroyed the device on his holiday on Risa . Their attempt to obtain the device was , in the end , the reason why Picard destroyed the Uthat , so that it would not fall into the Vorgons ' hands , thus completing the paradox . ( ) A predestination paradox occurred on Earth in the year 1893 , when " Enterprise " - D crewmember Lieutenant Commander Data , who had traveled back in time from 2368 , became trapped in a temporal vortex and had his body separated from his head , which remained in a cavern under the Presidio in San Francisco until 2368 . In that year , Data ' s head was discovered , leading the crew of the " Enterprise " to mount an investigation . This investigation led to the very time travel event which transported Data back in time in the first place , thereby completing the time loop . ( ) " In 2371 , the devastion of a planet in the Delta Quadrant due to a polaric ion explosion occurred due to a predestination paradox . Kathryn Janeway and Tom Paris were transported back through time by a subspace fracture to the day the explosion occurred . There , a subspace fracture opened and intersected with a polaric conduit and resulted in an explosion . The shock wave from the explosion dissipated into the past , which shattered subspace and created the subspace fractures in the first place . The following day , " Voyager " arrived at the planet , where the fractures were floating across its surface like icebergs . After Janeway and Paris disappeared through one of the fractures , the crew of " Voyager " constructed a device that could open the subspace fractures as a means of rescuing their crew . Ultimately , the crew opened a subspace fracture at the location of the explosion , which lead to the explosion that created the fractures and lead to the deaths of Janeway and the planet ' s natives . " This time loop was broken when Kes experienced a vision of what happened . This allowed Janeway to close the fracture before it intersected with the conduit , resulting in the creation of an alternate timeline where the explosion never occurred and " Voyager " never visited the planet . ( ) " Captain Braxton , a Starfleet officer from the 29th century , described this type of paradox as " A leads to B leads to C leads to A , " when attempting to explain the series of events which led to the destruction of Earth ' s solar system in his time to the crew of the USS Voyager . Finding debris from Voyager in the aftermath of the temporal explosion that destroyed the solar system , Braxton came to believe that Voyager was somehow responsible for the incident . In an attempt to change history and prevent the explosion , Braxton traveled back in time to 2373 to destroy Voyager . This action caused both ships to be transported back to 20th century Earth , where Braxton ' s timeship was stolen by an unscrupulous industrialist named Henry Starling . It was at this point that Braxton realized that it would be Starling who would cause the explosion , by taking the timeship to the 29th century without properly recalibrating its temporal matrix . " This time loop was eventually broken when the crew of " Voyager " was able to destroy the timeship moments before it traveled to the future . ( )