By 2379, McEwan served as a security officer aboard the USS Enterprise-E with the rank of ensign. In she was part of the Echo team under the command of Lieutenant Taurik which was sent to Tezwa's Linoka Forest to destroy the nadion-pulse cannon firebase located there. Ensign McEwan was known for being adept at stealth operations. (TNG novel: A Time to Kill)
On Tezwa, McEwan was part of the second two-week shift in the city of Alkam-Zar. Her first day there, she was moved to tears by the suicide of a Tezwan man. A young boy translated the man's singing as a Tezwan "sorrow-song," which he was singing in mourning for "the world" (Tezwa). The man's singing and death would haunt her throughout the rest of her time on Tezwa.
Two weeks later, McEwan was part of the mission that captured General Gyero Minza, the head of the resistance. A short time after that, McEwan was on the runabout USS Tunguska headed for Alkam-Zar when the Loyalists began their final assault. The runabout was hit from the ground and crashed with only Lieutenant Scott Fillion and McEwan surviving. Fillion was killed and McEwan was mortally wounded by the attacking Tezwan ground troops. Rather than allow herself and the runabout to be captured, she detonated a photon grenade, killing herself and destroying everything else present. (TNG novel: A Time to Heal)