After the Enterprise crew became infected with the polywater intoxication virus, causing them to lose control of their ability to inhibit their emotions and behavior, Wesley Crusher tricked MacDougal out of main engineering so he could take control of the area. The young Crusher then erected a force field, separating himself from the rest of engineering and preventing MacDougal or anyone else from entering the main control room. MacDougal subsequently assisted Commander Riker in disabling the force field and take back control of the starship.
Afterward, MacDougal tried to replace the isolinear chips removed by her infected colleague, Jim Shimoda. With the chips removed, the ship could not be controlled, which was made more crucial as the ship was on a collision course with a stellar core fragment. Data, though himself infected, was able to place the chips back more quickly, regaining ship control and avoiding a collision. She appeared to be unaffected by the intoxication as she was able to perform her duties without interruption. However, she was injected with the antidote. (TNG: "The Naked Now")
Under Chief Engineer Geordi La Forge, MacDougal was a duty engineer. She, along with Leland T. Lynch, were supervisors for the third shift. During the upgrade of the subspace phase coils, their team performed the final calibration needed to complete the procedure. In her final analysis, MacDougal noted a minor phase variation in the tertiary harmonics. This variation didn't affect the power output; however, Argyle recommended the continued use of test instrumentation for monitoring phase shifts. (TNG-R: "Galaxy's Child")
|Chief engineers of the starships Enterprise|
|Enterprise NX-01:||Tucker • Kelby|
|USS Enterprise:||Louvier • Scott|
|USS Enterprise-D:||MacDougal • Argyle • Logan • Lynch • La Forge|
|USS Enterprise-E:||La Forge|
|ISS Enterprise NX-01:||Tucker|
|ISS Enterprise NCC-1701:||Scott|
|USS Enterprise:||Olson • Scott • Chekov|
MacDougal was played by Brooke Bundy. MacDougal appeared to have been replaced as chief engineer by Lieutenant Commander Argyle in "Where No One Has Gone Before", also set in 2364, as she was not seen, heard, or mentioned after "The Naked Now". However, Commander William Riker claimed that he, as first officer, was the supervisor to maintenance of the ship's engines. He went on to say that he was guided by "one of our chief engineers: Lieutenant Commander Argyle, in this case", which supports that MacDougal was not replaced. The novelization of "Encounter at Farpoint" also has Argyle as chief engineer even though Bundy appeared in early audition footage. The practice of having more than one chief engineering officer on the Enterprise came to an end in 2365. Riker's involvement with main engineering lessened as well, once Geordi La Forge, a bridge officer, became chief engineer.
According to the script, her first name is Sarah.
In the novel The Buried Age and the short story "Meet with Triumph and Disaster" in The Sky's the Limit, she was described as having served as one of the USS Enterprise-D's two chief engineers under Captain Thomas Halloway in 2363, splitting her duties with Argyle. The Buried Age referred to her as Heather MacDougal.
MacDougal has appeared or been mentioned in other non-canon releases, such as Pocket TNG novel Ghost Ship, and Star Trek: The Next Generation comics from DC. In "Suspect", it was noted that she had been killed sometime between 2369 and 2371. Alternatively, the novel A Time for War, A Time for Peace establishes that MacDougal retired from Starfleet.