Matthew Ranklin and Conall O'Gilroy are agents of the British Secret Service.
The year is 1912. Europe, which has seldom had a period where someone wasn't fighting with someone else, is seeing a lull before what most fear will be a huge storm. Empires abound on the continent with the British Empire having the most power but not by much. France was a republic but thought of itself as an empire. Germany, Russia, and Austria-Hungary, as well as the Turks under the name Ottoman, opening called themselves empires. Everyone claimed they wanted peace but it was always peace on their terms.
With all the hostilities brewing, knowing who are really doing what became more important than ever and the government of His Majesty George V was largely bereft of the means of so learning. The Commander who would become known as "C" was putting together the first official Intelligence department, called the Secret Service, and was in the need for intelligent, independent men to become its limbs. Seeking suggestions from the various military and civilian departments, he picked the "candidates" he thought best suited for this new line of work. Sometimes they came of their own will and other times they were nudged into it. Ranklin was sort of in the middle.
Ranklin had been a captain in the British Army but had a short time before resigned his commission in the Gunners. His family under the control of his older brother had suffered huge financial troubles and was near bankruptcy which meant considerable difficulty for Ranklin in the officer corps as his fellow officers would talk and relations would be strained. As a result, it was strongly suggested by his superiors that Ranklin leave the Army and find work elsewhere. Since the military was all he had known for nearly 20 years, he chose a more lateral move from the British Army to the Greek's. It was there in a small skirmish with the Ottomans that Ranklin is found.
Like Ranklin, O'Gilroy too had served in the British Army but his service has lasted half as long and was as an enlisted man ("it was Corporal and an honourable dischard wid two good conduct stripes"). After that things took a bit of a turn as he came back to his native Ireland and decided to help his country get free of the English control. Still a half decade before the Irish Republican Army would get its start, smaller bands operated independently. Being smaller meant being less financed and that often led to "creative" ways to get funding.
It was during one such extra-legal procedure that O'Gilroy met Ranklin and though theirs was not an instant friendship, it grew on both of them. When it came to a close, Ranklin needed help and O'Gilroy needed new employment.