Lawrence Bacon is a London antique dealer and rumoured occultist, identified by Vincent Tuck as the leader of Alexander Roby's circle of friends, which included Malcolm Quarrie, Montague Edwards and Michael Coombes. Doctor Lionel Trollope's last letter implies that Bacon may know something about the Roby murders.

Tuck revealed Bacon's address to be 112 Liverpool Road, N1, and according to Vincent Tuck's report, Bacon once killed a man using black magic.

Tuck describes him as tall and heavily built with greying hair and a full beard. He looked about 55 years old in 1925.

When encountered by the canal on the night of November 27th 1928, Bacon seemed to be no older than 40. He used what appeared to be magic to kill a vagrant, and then, when challenged by Withers, called for Coombes before charging into the attack. Withers fired, but bullets seemed to have no effect on Bacon, who was chanting strange words and holding out his hands (which appeared to be change into the heads of snakes!).

Despite shrugging off the effects of the first few bullets to strike him, Bacon was eventually injured. As he fought desperately for his life, he trod on a loose stone and plunged into the canal. He did not resurface and was assumed dead.

After Bacon's believed death the investigators discovered the following:

• In Bacon's shop, the investigators found a number of interesting books and the Chime of Tezchaptl, before being forced to flee by the appearance of creatures that Andrew Saunders tentatively identified as Ghouls, coming up from his basement.
• In a letter posted the next day Wilfred Gresty thanked the investigators for 'the murder of Bacon', but it is not known how Gresty came to learn of Bacon's death. The December 8th edition of “Occult Magazine” carried an obituary for Bacon written under the pseudonym of “Perdurabo” (Latin for “I will endure”). This obituary was too well-written to have been the work of Gresty, unless he was faking his poor literacy in his letters to Doctor Bartlett.
• A few days after the battle at the canal, the characters later read of the The Canal Murders in the papers, and believed this was somehow Bacon returned. While the party declined to investigate this further, Nathaniel did meet with Cec Watts a reporter with the 'London World ' to see if he could discover more.
• After the death of Watts, the police went to Bacon's shop and found that it had been thoroughly ransacked.