Chan, an articulate senior detective nearing the end of his career, is taking care of the daughter of a witness killed by ruthless crime lord Po. Martial arts expert Ma is set to take over as head of the crime unit, replacing Chan who wants an early retirement.

Here though the idea is simple, and Red Cliff / Three Kingdoms form the basis and backdrop at which comedy finds its place. It's essentially a crazy little love story between an unnamed bandit (played by Ronald Cheng) who becomes Zhao Yun when the time travelling, titular Pandora's Box gets activated, and an immortal called Rose (Betty Sun) who is out to find The One true love, whom she believes to be Cheng's character. So time travel drops them smack into the Battle of Red Cliff, and part of the fun here is to identify the whole slew of cameo appearances by China and Hong Kong actors, who seem not to mind the very bit roles (one scene or two) to lend a helping hand at boosting the film's star attraction. And these appearances come quite fast and furious, together with almost a laugh-a-minute comedy that Lau weaves into the narrative, most of which are genuinely funny, until it started to run out of steam and paid not too subtle comedic homage to Hollywood films like Titanic, The Matrix and King Kong even. Needless to say the narrative itself is simplistic and delivered in a choppy manner, stringing together gag after gag, and the finale was quite off the mark with a sudden tribute paid to one of Lau's earlier and more famous works with Stephen Chow. Still, it did what it had set out to do, to help you relax and enjoy a rip-roaring time at the movies, so the objective's met and I've got little qualms about it since I honestly am admitting this was much better than expected, and had found myself laughing at some points with tears uncontrollable.