The first thing you will need to do is keep a constant eye on the Potential Recruits section of the Team menu. You will need to be on the lookout for a character called Callum Davies, who fits the role of Video Game Designer. He can be found in the Tower Hamlets borough.
Head for the Royal London Hospital and Callum will appear from a doorway there and you can speak to him. This will begin the recruitment process, but you will need to help Callum with a problem first. Albion is after him after he witnessed Albion tormenting and torturing some prisoners.