Henry was encountered on the train between Manchester and Inverness. he was carrying a bone whistle like Lawrence Bacon owned and was at first tricked, then intimidated to revealing all he know of the planned events at Loch Mullardoch which amounted to very little.

He had joined Lawrence Bacon's occult discussion group in London, which consisted of maybe 20 men, and through that had learned of the being Hastur whose return to Earth would bring wonder and glory to those who revered him. He was too frightened to attend the attempted summoning of Hastur at Springer Mound and after hearing that several men had died there he more or less dropped out of Bacon's circle prior to being told to travel to Inverness to attend 'a great and momentous occasion'. He had prevaricated about going to the extent that he was 4 days late when the investigators encountered him.

Lister was easily dissuaded from attending and left the train in the Lake District, abandoning his whistle. Dr. Bartlett believed that Lister suffered from necrophobia and his motive for being in the cult was a desire for eternal life, apparently promised by Bacon.