In 140 AD, twenty years after the unexplained disappearance of the entire Ninth Legion in the mountains of Scotland, young centurion Marcus Aquila arrives from Rome to solve the mystery and restore the reputation of his father, the commander of the Ninth. Accompanied only by his British slave Esca, Marcus sets out across Hadrian's Wall into the uncharted highlands of Caledonia to confront its savage tribes, make peace with his father's memory, and...

Since giving up his life as a government assassin, Robert McCall has struggled to reconcile the horrific things he's done in the past and finds a strange solace in serving justice on behalf of the oppressed. Finding himself surprisingly at home in Southern Italy, he discovers his new friends are under the control of local crime bosses. As events turn deadly, McCall knows what he has to do: become his friends' protector by taking on the mafia.