Joe "Cal" Callahan is a security expert.
- "Joe Callahan was tall, dark, built and unbelievably gorgeous. He also had a scar on his face that marred his perfect male beauty in a way that was hot but also made him more than a little bit scary." - Ashley, Kristen (2011-12-28). Heaven and Hell (Kindle Locations 11250-11251).
- Cal's story is told in At Peace
- The Promise, the story of his cousin Benny, also heavily features Cal including his wedding and the birth of baby Angie
- Heaven and Hell