Well, it’s August. These are the doldrums. The summer, as a movie season at least, is effectively over, and the fall hasn’t started yet. Perhaps for that reason, “The Hitman’s Bodyguard’’ seems just a little better than it is.

For the record, it’s a pleasing action movie that aspires to be something more, but doesn’t quite achieve its intention. But it is pleasing and better than routine, and it has a way of topping itself. So if, after about 80 minutes, you think the movie is offering you its big climax, that it’s giving you all it’s got, it’s not. It goes on to catch a second wind and gets bigger and wilder and more satisfying.

The movie also is a chance to appreciate Samuel L. Jackson in something close to his purest form. Other movies, after all, have other reasons for being. There are roles to be cast and actors to play them. But it’s hard to imagine any reason for this movie’s existing but for the fact that Jackson was willing to be in it. It’s impossible even to imagine it even making sense without the menacing joviality that he brings to it.

“The Hitman’s Bodyguard’’ pairs Jackson with Ryan Reynolds, and sprinkled throughout we get moments that suggest an attempt — by Tom O’Connor’s screenplay and Patrick Hughes’ direction — to turn the movie into a buddy action-comedy. But O’Connor and Hughes’ aren’t quite sure whether they’re making a buddy action-comedy or lampooning the genre, and so their attempt is stuck somewhere in between. This is less a problem than it sounds, though, because, lampoon or not, Jackson and Reynolds are good together.

Reynolds plays Bryce, a former CIA agent specializing in offering first-class (“Triple A rated’’) protection for corporate clients who feel their lives might be in danger. In an opening scene, we meet him in flashback, giving the deluxe treatment to a Japanese businessman. He and his team escort the gentleman to the tarmac and see that he is safely boarded onto his private jet. And then just as they are all congratulating themselves for a job well done, the businessman is assassinated through the window of the plane.

Anyway, two years later, Bryce needs a shave; his love life is nonexistent and his once top-flight business is a shadow of itself. Then one day, he gets a phone call from his estranged ex-girlfriend, an Interpol agent played by the French actress Elodie Yung: She needs him to escort a notorious hit man (Jackson, of course) to The Hague, where he is to testify against a horrible war criminal (Gary Oldman, of course). The only catch is that there are many dozens of heavily armed criminals and corrupt Interpol agents who want to make sure that this testimony never happens.

Aside from the principals, who are everything they should be, there is Oldman, who is appropriately repellent in a couple of key scenes; and Yung, who makes a nice impression of strength and purpose as the Interpol agent. In a sense, Oldman and Yung play dramatic characters in the midst of a comedy, but the filmmakers weave them into the flow. Meanwhile, Salma Hayek stands out in a comic role as the hitman’s impossibly vulgar, assertive wife.

It’s worth noting that there are lots of car chases here, and they aren’t boring. That qualifies as a rare achievement.

“The Hitman’s Bodyguard”

118 minutes

Rated R for strong violence and language throughout