Jonathan 'Jon' Levine is an agent for the American President.
He will be, eventually, though quite unofficially. Before that, well, he has a very interesting set of career fluctuations.
When we meet him in the first recorded adventure, he is, and will remain throughout the time we have to follow him, an investment manager. He is the owner and founder of Levine Investment Management, based out of Palm Beach, Florida; it is a firm that has over the years consistently provided returns for its customers a bit higher than more firms due to Levine's impressive skills and his dedication. His educational credentials include a BA from Syracuse followed by an MBA at Harvard.
Thanks for an FBI one-page memorandum about Levine, we learn that he speaks three foreign languages, Spanish, French, and German, and that he had previously served for a time as a U.S. Marine using OCS to become an officer, highest rank being Lieutenant. We are also told, listed under 'Psychology' that he is assigned the following traits: "Aggressive, Cocky, Flip, Savvy, Bold, Sophisticated, Clever, Brazen, Feisty, Intelligent, Glib, Alert, Perceptive, QuickThink, Interesting, Unique". As we monitor his actions during these intestesting escapades he finds himself in, we quickly come to realize that all of them are quite valid.
Levine does not seem to have especially fond memories of his short years in the Service, possibly because it ended with a bullet to the shoulder which still aches on occasion many years later. Or more likely the sorrow for the loss of the men under his command through no fault of his. Still, when given a chance to do something a bit more exciting than finding legitimate ways for his clients to grow their money - and make himself a very nice living - he realizes that the thought of something different was appealing; doubtful, though, that he anticipated it being this different.
Working alongside him from the beginning of Levine's new 'sideline' work for the Chief Executive is Alyssa Martin, an experienced physician specializing in internal medicine out of a small but always busy facility in South Beach. Though she does not know Levine at the beginning of these adventures, she definitely shares his not so fond memories of the Corps where she had also served years before. As she put it to the Major who showed up with an invitation which would change her life, she wanted to be a doctor back in the day and the only way she found to achieve that was through them. "I didn't join because I wanted to be a Marine, I didn't join because I was a patriot. I didn't join because I supported the war in Vietnam. I joined because I wanted to be a doctor. There was no other way available to me. I wasn't gung ho then-I'm even less so now."
So we have two people pretty well established in their own line of work with experience serving the country but less than fond memories of that service who are pulled into a new series of adventures. It definitely gets interesting from there.