Former CIA spy Bob Ho takes on his toughest assignment to date: looking after his girlfriend's three kids, who haven't exactly warmed to their mom's beau. And when one of the youngsters accidentally downloads a top-secret formula, Bob's longtime nemesis, a Russian terrorist, pays a visit to the family.
Ten-year old Agathe-Christine, or simply AC, prefers to be on her own. AC fancy mysteries, and from the basement in the building, where she has just moved in, she has established a small detective bureau. AC´s first mystery appears to be simple to solve, but before long AC finds herself involved in a much more complicated affair, than she could have ever foreseen.