Lawrence was one of the partygoers on Grallista Social when the Fifth Doctor and Peri Brown visited the planet. He was near the spaceport when the Viyrans came to cure a mutagenic virus. Since he didn't know what they were, he decided to make a run for it. He met Peri when she accidentally hit him with her car. He was also infected by the disease at this point. He was cured by the Viyrans and his memories of his infection was removed. (AUDIO: Mission of the Viyrans)