The story follows a one-time bullied geek who grew up to be a lethal CIA agent (Dwayne Johnson), coming home for his high school reunion. Claiming to be on a top-secret case, he enlists the help of the former "big man on campus" (Kevin Hart), now an accountant who misses his glory days. But before the staid numberscruncher realizes what he's getting into, it's too late to get out, as his increasingly unpredictable new friend drags him through a world of shootouts, double-crosses and espionage that could get them both killed in more ways than he can count.