Mystery, intrigue, and romance abound in this paranormal series that follows members of the Alpha Force-a secret branch of the military mostly composed of shapeshifters. An essential part of the U.S. defense forces in the United States, this undercover, elite, supernatural team uses its power to help investigate any major and mysterious crimes that cross their path, all while battling-or finally giving into-their passions. Hawk shifter Lt. Autumn Katers is proud to be a member of the Alpha Force-a highly covert military unit made up of shapeshifters like her. Her new mission? Get close to bestselling thriller author Logan Valliere. His latest book's plot features a special ops team suspiciously similar to the Alpha Force, and Autumn has to find out who's been helping him with his research. Flirting with Logan is a natural part of the job, but she never imagined she'd feel so attracted to her sexy subject. Giving into the temptation to go him with him can't hurt her mission-but might ruin her future with Logan if he finds out how she's deceived him. The events of Hawk's Challenge (Alpha Force #3.5) take place after the third book in the series, Guardian Wolf.