In 2372, she was aboard the USS Defiant during a trade arrangement with the Karemma. When the mission started she handed over the result of the last weapons drill to Worf and got orders to bring the response time down by at least fifteen percent. Before the weapons drill was finished she noticed two starships enter Defiant's sensor range and identified them as Jem'Hadar.
After Defiant went into red alert, she took the helm position when Jadzia Dax needed to increase sensor range from another workstation. While Defiant was in pursuit of the Jem'Hadar ships in the atmosphere of a gas giant, she steered the ship up to within ten kilometers from them. When Defiant was attacked by the Jem'Hadar she had to report to Captain Benjamin Sisko that impulse power was offline and Defiant was losing altitude. Although she tried to use the thrusters to compensate, they did not regain altitude.
When Carson reported that hull pressure was increasing above nine million GSC, she was ordered to take Defiant to a higher altitude. While she performed this maneuver they were attacked by the Jem'Hadar and lost main power. Carson had to report to Captain Sisko that Boyce and Peterson died during the attack and gave Kira Nerys a medkit so she could look after Sisko, who took a nasty hit.
When a medic was needed Carson tried to get one, but the communication system was down. When she tried a door it would not open, but with the help of Worf she managed to force it open and left the bridge. Carson managed to get the medic to the bridge where she watched him helping Sisko.