The Third Option is Vince Flynn's third novel, and the 2nd to feature Mitch Rapp, an American agent that works for the CIA as an operative for a covert counterterrorism unit called the "Orion Team". The first in the Mitch Rapp series American Assassin, was written later, but was a prologue to Kill Shot.
Vince Flynn wrote less than 4 novels.
He wrote at least 3 novels, but there's no indication that that was all he wrote.The system has problems with "less than" stats.