A father and his son come across an alien called CJ7 by chance and end up with it in their lives. The animated film draws on Stephen Chow's 2008 comedy hit CJ7, keeping the basic idea of that story while building a fresh plot around it. In this version the alien visitor takes on the role of guardian of the environment, and its efforts turn toward rescuing the whole planet. The result is a family tale about a parent, a child and an unusual companion, carried into an environmental adventure.