The Professional is a paperback book in the Spenser Series by Robert B. Parker, published by Penguin Publishing Group in 2010. This trade paperback spans 352 pages and falls under the genres of thrillers, crime, and mystery, specifically focusing on private investigators. With a publication year of 2010, this book follows the protagonist, Spenser, as he navigates through various detective cases and intricate crime plots, captivating readers with its gripping storyline and engaging storytelling.