Scott Rutherford is an agent with MI6.
Back in the days of his activities, the mid-1930's, it was known as the Secret Intelligence Service - Section 6 - aka SIS(6) but though it would undergo name changes a couple of times, it is the same agency. During the period that Rutherford worked for the department, it was run by Sir James McKay, described many times as a dout Scot and at least once as cantankerous, and had been for quite some time.
Rutherford is described early on as "aged thirty two, single, lived with his parents in Portsmouth when not on active service. He had been an outstanding student at the local grammar school resulting in a scholarship to Cambridge University where he gained a BSC (Hons). Spoke three foreign languages fluently: German, French and Spanish with passable Italian and Russian. He had excelled in sports gaining his 'blues' for rugby (his preference being football - an ardent Arsenal supporter), and a member of a victorious boat race crew against Oxford. He had also found time to become a Bisley marksman". Also that "he had a penchant for acting - he had been a member of the Cambridge Dramatic Club".
We further learn that his father had been a naval officer and it had been expected that the young Scott would travel that way as well but he chose instead "to join the Royal Marines where he swiftly rose to the rank of Captain. His exceptional prowess was brought to the attention of Sir James who took him under his wing and had him transferred to SIS training school where he distinguished himself."
Rutherford is described in several places as being a "devilish handsome chap" or, as the primary assistant to Sir James would put it when she had to meet him on several occasions, "the most ruggedly handsome man she had ever met". He stood 6' tall, was usually immaculately tailored, and had an Olympian athletic figure".
Considering the kinds of trouble that Rutherford will become involved in, he will need both his athleticism and his looks and charm on several occasions.