Plan B: A Nick Heller Story, by Joseph Finder, is free to pre-order in the Kindle store. Looks like a teaser story to get you interested in
Buried Secrets, which releases June 21. He has another book,
The Zero Hour, coming out this month, but it is a different series/character line.
Book Description
An original short story by Joseph Finder, New York Times bestselling author of Buried Secrets and Vanished. "Plan B" finds private spy Nick Heller in Barcelona, Spain on a rescue mission. The target: a walled compound with state-of-the art-security. The object: a teenage girl, held against her will. The plan: get in and rescue the girl and then get out -- without tripping an alarm or alerting the army of guards. But even the best designed plans can go wrong. Which is why Nick Heller always has a Plan B.