Trij was a 24th century female Klingon captain.
In 2384, Trij was contacted by Gwyndala, who informed her that a weapon aboard the USS Protostar had been activated and was causing an entire Starfleet armada to lose control of their ships and fire on one another. Gwyn requested the captain's help, in not only trying to prevent the armada from destroying itself, but also contacting other non-Federation allies. Gwyn begged the captain to send transports, freighters, shields, or anything else that would slow the attack Starfleet was inflicting upon itself.
When Trij asked why she should help, Gwyn replied that in the infinite of space, everyone needed to know that there was a place that would except them all, no matter what their differences. Gwyn argued that without Starfleet, the Federation would crumble and so would that dream. Gwyn argued that if the Federation had ever helped Trij's people, the way they’d helped her and her friends, then Trij would hear her words. Gwyn argued that Starfleet needed assistance, or it would not survive.
After Gwyn's speech, Trij abruptly ended the call, then later arrived at the armada, just in time to shield the USS Dauntless against photon torpedoes. Trij then opened a channel and declared, to Starfleet, that "the mighty Trij" offered them salvation and told them to prepare to beam off their ship.
In addition to her own Klingon Bird-of-Prey, Trij was accompanied by other ships belonging to the Ferengi Alliance and the Gorn Hegemony, as well as a Petarian bulk freighter, a Tellarite cruiser and a Vulcan Suurok-class vessel.
Unfortunately, Starfleet vessels automatically sent out a distress call when they were in danger, which meant that more and more Starfleet ships began arriving at the scene, only for them to be contaminated as well. (PRO: "Supernova, Part 1")
Refusing to withdraw, Trij and her crew kept on valiantly protecting the Starfleet ships when their Klingon Bird of Prey's shields were severely depleted. Fortunately, Trij's Klingon Bird of Prey, and the surviving alliance ships were spared from meeting a grisly fate when the USS Dauntless, and the other Starfleet ships were finally freed from the construct's corruption, when Hologram Janeway sacrificed herself to destroy the USS Protostar by detonating the proto-core while at proto-warp while also ensuring that the USS Protostar's crew had managed to survive in a shuttle. (PRO: "Supernova, Part 2")