Dr Teal was an engineer who joined the Guild of Engineers when London was controlled by Nomad leader Nicola Quercus.  t appeared in A Web of Air, in which he was sent to Mayda to study the funiculars that allowed houses on the Casas Elevado to move up and down, which he hoped London could use for their elevators. 

However, he was secretly working for a new branch of the Guild called the Supression Office, that aimed on stopping other technologies, such as flight, develop in case they were used against London.  He also assumed the role of Vishniak, a killer who for unknown reasons didn't want flight to be developed.  He had killed Edgar Saraband, and when he found out Arlo had been helping him, he went to Mayda to kill him.  He used Fever to find out if he was building a workable machine, and tried to kill him on Thursday Island.