A Debt of Honor

takes place during DS9’s “Shattered Mirror”

While trying to make the Defiant ready for its first engagement with the Klingon-Cardassian Alliance, Smiley and the other rebels get an offer of help from a most unexpected source—a Klingon old enough to remember when his own people were the ones enslaved by the Terran Empire. Kruge explains that he wants to restore the honor of David Marcus, whom the Alliance portrays as having betrayed his own people. Kruge knows Marcus was an honorable warrior who had helped the Klingons resist Terran occupation—nothing more. Dax explains that Marcus never expected the Klingons to be able to turn around and conquer Earth because he didn’t count on Cardassian involvement. Through a mind-meld Tuvok discovers Kruge’s story is truthful. Together with Dax and Bashir, Kruge is able to delay the Alliance long enough to enable the rebels to get the Defiant operational, although Kruge is killed in the battle. Afterwards there’s a discussion on the subject of an afterlife. Dax hopes Marcus has found some measure of peace, because the enslavement of humans and Vulcans wasn’t really his fault.