Henri Koskinen, intrepid insurance mathematician and adventure-park entrepreneur, firmly believes in the power of common sense and order. That is until he moves in with painter Laura Helanto and her daughter . . . As Henri realises he has inadvertently become part of a group of local dads, a competing adventure park is seeking to expand their operations, not always sticking to the law in the process . . . Is it possible to combine the increasingly dangerous world of the adventure-park business with the unpredictability of life in a blended family? At first glance, the two appear to have only one thing in common: neither deals particularly well with a mounting body count. In order to solve this seemingly impossible conundrum, Henri is forced to step far beyond the mathematical precision of his comfort zone . . . and the stakes have never been higher . . .