What a fantastic idea for a movie. Captured hitman Darius Kincaid (Samuel L Jackson) agrees to testify against alleged war criminal Vladislav Dukhovich (Gary Oldman), but in order to keep Kincaid alive a compromised Interpol must call upon the assistance of disgraced bodyguard Michael Bryce (Ryan Reynolds), whose past missions were consistently imperilled thanks to the very killer he's now tasked with protecting.

It's a terrific concept, an amazing cast and, unfortunately, a spectacularly disappointing film.

The odd-couple buddy action-comedy format has given us some great films over the years, including several featuring Sam Jackson himself. The mid-90s classics Die Hard With A Vengeance and The Long Kiss Goodnight saw the star paired with perfect yings to his yang. First it was Bruce Willis' no nonsense NYPD cop John McClane, and then Geena Davis' homemaker-cum-assassin Charly Baltimore. Both flicks offered that perfect blend of high personal stakes, high-octane action and high quality dialogue that, when mixed together, added rare complexities to the genre's traditionally two-dimensional character archetypes, and delivered sequences that could make you laugh, wince and grip your armrests until your knuckles turned white.

In The Hitman's Bodyguard, by contrast, the overwhelming feeling is that while writer Tom O'Connor understood all the ingredients necessary to make an entertaining blockbuster, he failed to appreciate the subtleties of how to best combine them. And the ingredients really are all there. The film's premise is tailor made to deliver conflict between its leads (to say nothing of the non-stop threats from the villain's henchmen). Yet everything about their relationship feels forced. Ryan's by the books persona sits uncomfortably with the actor's natural sarcastic schtick, while Jackson's foul-mouthed tirades lack both the venom and the wit to carry any real force.

What follows features an awful lot of shouting, none of which ever feels like it really matters. Pair that with a truly staggering degree of nonchalance during every fight scene, and The Hitman's Bodyguard ends up a movie robbed of any sustained drama or tension.