Lilt assisted Takis in protecting the Resting Ones from graverobbers. He was happy interrogating prisoners. He enjoyed questioning Natasha Stengos and Grigory when they tried to take back Arthur Stengos, Natasha's father, as they were part of a "Tranquil Repose Freedom Fighters" group.
He agreed with Takis' suspicions that things hadn't been the same since the Great Healer, who was really Davros, took over Tranquil Repose. They believed something had to be done to stop Davros. Unknown to him or Takis, Davros was turning Resting Ones into Imperial Daleks and food for starving planets.
Takis and Lilt sent a message to the Renegade Daleks that Davros was on Necros and they arrived to take him. Orcini, an assassin sent to kill Davros, detonated a bomb to destroy the Daleks in hibernation. This also destroyed Tranquil Repose's tombs.
The planets needed the food Davros had supplied, so the Sixth Doctor showed Lilt and the other Tranquil Repose employees how to farm the weed plant, which produced protein. (TV: Revelation of the Daleks)