Harry Seddall works in the Intelligence division of the Ministry of Defence.
Some who know him say he IS the Intelligence division. Others say far worse things about him. He doesn't say much about it one way or the other, showing he cares very little of what people think of him.
Somewhere around forty, described as a young-old man, he looks the antithesis of a dashing spy. He has mousy, thinning hair on a too round face. His clothes are off the rack, seldom properly ironed, and ill fitting, poorly buttoned with collars that went wherever they wished. His mouth seems set permanently in a cynical smirk and his entire demeanor makes him seem either lazy or just up to no good. "He seemed slovenly, idle, and disreputable; and he looked clever."
When one man, an intelligent observer of people and their habits, was asked what he thought Seddall dealt with in his work, the man replied, "I think I would be wiser not to find out."
In another scene, Seddall tells a man to contact him via Military Intelligence, asking for Colonel Seddall. When the man expresses surprise about Seddall was in the military, he replies, "I'm not sure that I am, and neither are they [the military]. We never have been."
He really does not care whether he works alone or with others but with his often caustic comments and his apparent sloth, he is often alone because others shy from working closely with him. He is not, however, a mean or angry man, just one who knows what needs to be done and does it.
Seddall survives the many enemies his attitude has created over the years by the fact that he is just that good at his job. If there is a spy to be caught or a mole to be uncovered, Seddall is the man to call. Just don't expect to like him while he's doing it.