My first Mulligan novel, Rogue Island, won the Edgar Award and the Macavity Award and was a finalist for the Shamus, Anthony, and Barry Awards. Most reviewers say Cliff Walk is even better. You can purchase the novels here.
The third novel in the series, Providence Rag, will be published in hardcover and e-book editions by Forge in March of 2014.
You can learn more about Steve Berry and his work here.