For a long time, Coombes was known as only 'The Tall Man' to the Investigators.

A tall dark-haired man with sharp features is following the investigators. He made his first appearance after Dr Bartlett returned from Herefordshire.

First he turned up in Dr Bartlett's street, pretending to be a taxi driver, looking for the Doctor's house.

Then he appeared at Victoria barracks with a parcel for Captain George Withers. The parcel contained a house brick - and was apparently delivered purely to identify Withers' billet.

Thirdly he intercepted Andrew Saunders during a taxi ride and threatened the curator with violence if he and his friends didn't “forget all about this business”. He also said “You have no hope of stopping what these men intend, and any attempt will only result in pain”. He stayed in the shadows throughout, so Saunders never got a good look at his face. Saunders reported this to the police.

Finally, he accosted Nathaniel Browne in a bookshop and implied that he had killed Frederick Long, which would appear to have required him to travel from Weobley to London in less than an hour. Browne reported this to the police and gave Detective Inspector Andrew Taylor a good identikit picture of his face.

The tall man is English, working class and apparently violent. He wears a long dark coat over a cheap suit, drives a non-descript black car (possibly a Morris) and has unkempt, greasy black hair.

In addition to these sightings, one of the suspects in the murder of Doctor Lionel Trollope fits his description.

Due to information provided by Delia Hartston, the Tall Man was tentatively identified as Michael Coombes, an associate of Lawrence Bacon.

When Wilfred Gresty sent his second letter to the investigators he promised to detain Coombes to prevent him from acting as a bodyguard to Bacon, and indeed when Bacon was encountered he called several times for Coombes before combat broke out.

Coombes was encountered again in the palace in Carcosa, where he appeared to be using the corridors as his personal hunting ground, having killed at least one servant and pursuing Yolanda. He taunted the investigators, and at this point his identity was confirmed.

In the end, Coombes assaulted the investigators in the maze in the English Garden, which was the exit from Carcosa to the real world. There he stabbed and seriously injured Andrew Saunders, prior to a shotgun blast from Yolanda which may well have killed him. Unfortunately Saunders fell through the gate at this point, and his final fate is unknown, although even if he survived he appears to be irrevocably trapped in Carcosa.