On behalf of General B'vat, the Human geneticist Amar Singh experimented with augmented Klingons in 2409. They broke out from the facility on H'atoria, and fled, seeking a cure for their affliction. (STO mission: "The Ultimate Klingon")
The Augments joined forces with B'Vat again. B'Vat had the kuvah'magh, the fated Klingon savior, embodied by Lieutenant Miral Paris, abducted and taken to the Gateway system. B'Vat forced the cuffed lieutenant through the Guardian of Forever, which brought them to the year 2270. (STO mission: "The City on the Edge of Never")
B'Vat allied with his younger self, and placed Lieutenant Paris in Captain B'Vat's care. Samples taken from her blood allowed the Klingons to reverse the effects of the Qu'Vat virus and restore their forehead ridges. One month after her arrival, the Augments brought the IKS Worvig from the future with them. Paris was confined aboard, and Captain B'Vat assumed command.
One month later, the Worvig led an attack on USS Enterprise in the Oleum star system. The untimely destruction of the Enterprise was prevented when the Guardian of Forever sent a Starfleet vessel from 2409 into the past to repair the timeline. The Starfleet ship defended Enterprise against attacking D7-class battlecruisers and chased the Worvig away from nearby planet into the system's asteroid belt. The Worvig used its cloaking device to evade capture, while four more contemporary battlecruisers engaged Starfleet.
When these were destroyed and the Worvig disabled, the Starfleet vessel deployed an away team to retrieve Lieutenant Paris, whose combadge they had used to track her, and the Worvig, with. The away team faced a mixed QuchHa' and HemQuch Augment crew. After subduing Captain B'Vat on the bridge, he informed them about General B'Vat's presence and the Augments' plans, and switched sides. He left Worvig, and the away team proceeded to the mess hall, where they killed the general and his guards, and freed Paris from her two-month ordeal. She was happy to have helped her people, and the Worvig was abandoned. After beaming back to the Starfleet vessel, the Worvig was fired upon and destroyed. The Starfleet ship travelled to the Gateway system, where it faced resistance from six more Klingon battlecruisers before Enterprise returned to occupy the Klingons until the future starship returned to its time. (STO mission: "Past Imperfect")