The party was contacted by Gresty on a number occasion prior to meeting the man in person.

• Somebody signing himself 'W. Gresty' sent a letter to Doctor Frederick Bartlett from London. It arrived on November 20th 1928.
• On November 29th 1928, Dr. Bartlett received a second letter from Gresty, who signed himself 'Wilfred Gresty'. It is notable that at the time this letter was received Bacon's death was not public knowledge.

From these letters several facts can be learned about Gresty.

• Gresty considers the investigators as friends, despite apparently never meeting them.
• Gresty was once a part of the same group as Lawrence Bacon, Malcolm Quarrie, Alexander Roby, Montague Edwards and Michael Coombes.
• This group is no longer together. Gresty still has contact with Bacon and Coombes, but Quarrie has gone away.
• Gresty is from the West Country and knows Hillary Quarrie.
• Gresty hates London.
• Gresty seems not to share the beliefs of the rest of Bacon's circle, instead serving 'the Goat'(possibly Shub-Niggurath).
• Gresty hints as some kind of power struggle involving himself, Hillary and a man called Atkinson.

In December 1929, Gresty was arrested for assaulting a verger in Christ Church, Spitalfields and brought before the magistrate. The report of his arrest in the newspaper brought the investigators to the court to see their mysterious correspondent at long last.

The investigators learn that Gresty's address is 127A Brick Lane, London EC2. Gresty, appearing nervous and penitent, admits to the trespass and breaking and entering charges but alleges that his knocking over of the verger, Mr. Unsworth, was unintentional and unnoticed. The Magistrate, swayed by Gresty's clean record and obvious remorse, gives him a token fine.

Gresty, as it turns out, is a worshipper of what he refers to as 'The British gods', of which the foremost appears to be Shub-Niggurath, also called the Black Goat. Gresty claims that the architect of Christ Church (and several other churches in London) Nicholas Hawksmoor was himself a follower of 'The British Gods' and built these churches as much, if not more, as an altar to them rather than to any Christian God. He reveals that he was praying to 'the Goat' when he was accosted by the verger and that the cuts on his hands were a part of that pagan prayer.

Gresty claims that he was sent to London by the cult leader, Atkinson to act as a spy after Malcolm Quarrie defected from the worship of Shub-Niggurath to that of Hastur, and that he successfully infiltrated Lawrence Bacon's circle. Gresty became the flatmate of Bacon's thug Coombes and as such was able to learn almost everything the Hastur cult was up to. Gresty is very proud of his success, but hates London and wishes to return to Goatswood.

A few days after his court appearance, Gresty returned to his home near Goatswood, Gloucestershire. In an attempt to gain control of the Goatswood cult, Gresty convinced Atkinson that Hillary Quarrie needed to be eliminated, and aided the aged cult leader in summoning one of Shub-Niggurath's young, a gigantic tentacled abomination, to assault Nug's Farm.

With the aid of Doctor Frederick Bartlett and Captain George Withers, Hillary used sorcery to turn the creature upon its summoners, and it returned to the hamlet of Mercy Hill, where is is believed that it killed all those involved in its summoning, including Atkinson and Gresty.