eventual discovery of time travel. Later, Lisa sets to work at the cryonics lab, attempting to reconstruct the chemical compound. Production After series creator Chris Carter and Howard Gordon completed the script for "Unrequited", the former assigned the latter to develop a new episode with David Greenwalt, who was new to the show and had been hired a few months prior as a producer. Gordon and Greenwalt met up and began writing what would become "Synchrony". During this process, they struggled to find a good plot, and they almost submitted a story involving an inmate swapping bodies with another man to escape prison. However, Gordon was unsatisfied with this storyline, as he believed it to be far too derivative of his previous episode. Eventually, the duo read an article in Scientific American about time travel: the article claimed that while classical physics does not allow for temporal displacement, quantum physics does. Gordon and Greenwalt were intrigued by the concept and decided to re-situate their episode around a related premise. Gordon decided that the most affecting and X-Files-like story should involve a time-traveler who "turns out to be you". Howard was inspired to make the main antagonist a regretful scientist after hearing the story of Manhattan Project physicist J. Robert Oppenheimer berating U.S. President Harry S. Truman for using atomic bombs on Hiroshima and Nagasaki in 1945. This prompted Gordon to rhetorically ask: "What if Oppenheimer could go back to the past and 'uninvent' the bomb?". Soon, Gordon and Greenwalt began pondering fatalistic determinism brought about by the ability to see the future, with the former noting: "Life itself is about the unknown and discovering what is in front of us. But if everyone, or maybe some people, knew what would happen, that would create a new set of horrors, and it would need to be stopped". The script for "Synchrony" took over a week to write, with some day-long sessions lasting over 15-hours. Gordon and Greenwalt were also assisted by fellow writers Ken Horton, John Shiban, and co-executive producer Frank Spotnitz. A few days before filming was slated to begin, Gordon was still frantically reworking the teleplay; during these last-minute rewrites, he removed a number of elements, including two "useless characters" (one of whom was a Stephen Hawking-esque scientist in a wheelchair)a move that he claims "really tightened up the story". David Duchovny later revealed that a few of the