Philip Jordan is an agent with MIx.
Also written as MIX and MI.x, this small branch of British Intelligence is definitely not MI5 or MI6 as the members of the group discuss how the cases they handle fall between the two larger, more well-known organizations, or perhaps act as a bridge between the two. Certainly the cases that Jordan works for them seem to stray into both jurisdictions. The agency is headed up by a person known as "One". Jordan's immediate boss, handler, and to a smaller degree colleague is a man named Horton.
Jordan comes to work for MIx after an impressive period working in the OSS during WWII but his route to his career took a decidedly unorthodox route - he spent several years in various prisons. What made it more unorthodox was that it was planned by him all the way.
His story is a sad but all-too-frequent one. He heads to war leaving behind a wife he loved and returns a couple of years later to find her involved with his best friend. The tale veers from the norm, though, when it turns out his friend is also an agent for the Communists and a drug dealer to further his plans. She is a target and the drugs she is given eventually destroy her mind. Jordan wants revenge. He gets it rather easily on him former friend but he wants to go up the chain.
Jordan did not know at first that his targets were spies, using drugs and other offenses to finance their activites. To Jordan, they were criminals and to destroy them, he needed to get inside which meant he needed to be a criminal, too. In his days with the OSS, he had been taught by the very best safecracker how to open most anything and he used that skill to make a name for himself. He also made sure he was caught so his record would reflect his activities. He spent several years in prison for crimes he committed all to prove he was as crooked as he needed them to think him.
It was when his activities took him to England and one step away from the Big Man that MIx stepped in. They knew the man Jordan was after was more than a crime boss and they wanted more than just an arrest. They approached Jordan with the truth and he reluctantly was in.
Once his personal crusade was concluded, as told in the first adventure, he was in need of a new life. He had been a crook only to further his revenge. He had no desire to continue as one. MIx knew a good agent when they saw one and they made him an offer.