Grant is an agent with the British Secret Service.
The period of activity for this highly respected and immensely tenacious operative is the 1950s when the Cold War was at its chilliest with the men and women who plied the clandestine trade put their lives on the line constantly by working in secret and usually in solitude. There were telephones for communication but international service was time-consuming with callers often having to wait hours for a connection. Television was in its infancy while radio was common but communication through it still took large mechanisms poorly suited for transport. Satellites were just being dreamed of. All this meant was that it was not uncommon for an agent to be sent out on a mission and not heard from again until he/she walked back in months later, if ever.
Grant is one of the civil servants who thrived in this danger. His boss, designated F2 at the department he works for, is a friendly enough man to Grant but likely reserved because he often sent Grant into near-suicidal situations. Grant lets us know at the end of one mission that F2 was used to his operative walking into his office and proclaiming, "I have the honor to report that the operation was carried out with complete success". He adds that "if you cannot report complete success, then you ar elying stiff and cold in some foreign field".
Grant has no immediate family of his own, devoting his life to his profession and not wanting to have to worry about a loved one back home, or she him. He does enjoy a friendly relationship with his brother and spends time with him and his family, being at times almost a surrogate.