Pike Logan is an agent with the Taskforce.
Certainly he is at the start of the series and while his actual affiliation with that small agency changes quickly, his closeness to it keeps the statement close enough to accuracy to stand.
The Taskforce is a small department put together by Presidential decree designed to handle the most urgent and secret of assignments, missions that are so sensitive that Congressional oversight is a danger. Answering to the National Security Council, this band of mostly elite soldiers can go places that most "legitimate" agents cannot and get out alive. Their check in a world of checks and balances is that they cannot initiate their own tasks and must be approval before heading out. Once done, their only criteria is to succeed.
One of the founding members of this force is Pike Logan, a man given that nickname many years before and finding it far less objectionable than his given name. As described in the first book, "his assignments read like a who's who of the military elite". He joined the military and immediately volunteered for Ranger service. From there he moved to the Special Forces in Okinawa for a couple of years and then Delta Force for more than a decade. Serving was what he loved doing and he was incredibly good at taking nearly impossible missions and pulling them off.
During that time he met a woman, fell in love, married, sired a young daughter, and then, while on a mission for the Taskforce, learned of their horrific murder back home. Suddenly his world crashed around him. His interest in anything other than escape grew more and more, his irritability and anger growing enough to push away his friends and his career.
Most of that happens in the earliest part of the first book. What follows and makes up the majority of the series is Pike Logan's return to life and his finding new purpose. Most of that is at the hand of one incredibly interesting young woman, Jennifer Cahill. A woman in her mid 20s, Cahill is finishing up college after a brief interruption and trying to fit in with the younger people in her class when a chance meeting Logan sees her saving his life in a bar fight. This is a fortunate act of kindness because soon thereafter she is in need of saving and Logan reluctantly returns the favor. It does not take long for the two to make up one enjoyable and efficient team.
At the end of the first book, when Logan has a chance to return to the fold of the Taskforce having worked again with them in the first adventure, he decides to instead form a company partnered with Cahill, willing to work with the Taskforce on assignments but also able to handle other jobs should they decide. Together Logan and Cahill are a great duo.