In 2154, Laneth was a Lieutenant stationed on the Qu'Vat Colony. She was selected to be one of the first to have Doctor Antaak to inject her with the Qu'Vat virus - which contained Augment DNA. This caused her to lose her forehead ridges and gain a more human like appearance. She was one of the Klingons selected by General K'Vagh, son of Wor'maq to participate in the raid on the United Earth Starfleet starship Enterprise along with K'Vagh's son Marab. Despite the Klingon attempt to destroy the Enterprise by accelerating the ship to the point where the warp core would breach, chief engineer Commander Charles "Trip" Tucker was able to shut down the engine and purge the Klingon programming.
Returning to the Qu'vat colony, she told K'Vagh that for the first time since she was a child that she had felt fear, as had the other members of her team. By then seriously ill, she told K'Vagh that the experiments had caused her to become weak. K'Vagh tried to reassure Laneth that Dr. Phlox was working on a cure, but he also told her that even if the cure did not restore their forehead ridges, as long as he was alive, Laneth and the others would always have a place in the Empire. Phlox was able to cure the virus, but Laneth and the others infected with the Qu'Vat virus were left with their more human-like appearance. (ENT episode: "Divergence")
By 2165, Laneth was a Captain. As a QuchHa' assigned to command a ship with other QuchHa', the ship had very limited resources. As the HemQuch Klingons began to oppress her and her fellow QuchHa'. Laneth decided to fight back, and joined General K'Vagh and General Kor, son of Kaltar in fighting against the HemQuch. Working with the Klingon pirate Lokog, the rebels attempted to defeat the HemQuch with Ware technology, however the HemQuch discovered how to permanently destroy the Ware.
The rebel forces battled to hold their territory. In November 2165, Laneth, K'Vagh, and Kor were invited by the new Chancellor Khorkal to parlay in the Klingon High Council chambers. During that meeting, Khorkal ordered the QuchHa' to resolve the issues with with a duel. Laneth volunteered to fight for General K'Vagh against Councillor B'orel, who was leading the HemQuch persecution of the QuchHa'.
Able to easily provoke the young, hotheaded B'orel, Laneth was able to kill the councillor. Khorkal then declared that the QuchHa' could remain in the Empire, that noble QuchHa' could retain their lands and titles without challenge, and that K'Vagh could take B'orel's place on the High Council and act as the voice of the QuchHa' on the council. Laneth vowed to herself to continue the fight to ensure QuchHa' rights, and hoped that the Empire would unify so that the day the Klingons turned their attention outward again, the United Federation of Planets would see a very different kind of Klingon. (ENT - Rise of the Federation novel: Live by the Code)