One, two three four…slash-mark to denote “five.”

That’s what a B-movie shoot-em-up often invites you to do, just keep track of the body count.

Six, seven, eight, nine, another slashmark — “TEN.”

“Shrapnel” is a straight-up “They’ve taken my daughter” vengeance thriller, less logical and a bit on the absurd side, but a picture that allows Jason Patric to shoot-up black SUV-convoys full of Mexican cartelions as they come to his remote ranch to “send a message” when he has the temerity to appear on TV to ask for his daughter’s safe return.

It starts with a frantic phone call, his darling effed-around-and-found-out teen has ducked across the border to lawless Juarez to party. Now, she and her friend have been “taken.” Not that she has time to say that.

Sean Beckwith has to get in his truck, drive over the border to the police impound lot and find the 18-year-old’s car, with only her sunglasses left behind, to confirm his worst fears. The Mexican cop (David DeLao) is too happy to play the racist American card in dismissing Sean’s frantic fury.

“We see this all the time,” Officer Montoya mutters. Then a “gringo” shows up and “points his finger at all the dangerous ‘brown people’ living just across the bridge.”

Well, that tears it. And that settles it. The “cartel” may have taken daughter Leigh and her girlfriend Billie. But the cops are in on it.

It’s not much comfort chatting with the U.S. Consul (Jack Forcenito) or even an old comrade-in-arms (Cam Gigandet) who suggests they “waterboard the cop” and “burn the whole f—–g town to the ground.”

Did I mention Sean’s a retired Marine Corps colonel? Yeah, he has “special skills.” So after he and wife Susan (Kesia Elwin) go on TV and the “Los Mercenarios” cartel kingpin (Mauricio Mendoza) sends his brother (Guillermo Iván) and his minions north in a black SUV convoy to slaughter the impudent gringo, at least the brother knows to be wary.

“Never underestimate a man that spent the majority of his life working in a profession where the men tend to die young.”

Thus, the allegedly “ex-Mexican-military” gangsters approach the log ranchhouse with caution. Too much caution. SLOWLY.

Eleven, twelve, thirteen, fourteen, slash-mark “fifteen.”

The shootouts are illogical and the many deaths perfuctory, save for the odd exploding head. The entire middle of this short thriller is that ranch gun battle, with a house surrounded and covered from every angle, yet wife and younger daughter are able to slip out a window, and a lone sheriff rolls in to fire his shotgun-that-never-needs-reloading.

Sixteen, seventeen…

Director William Kaufman (“The Hit List,” and “The Channel,” which was better than this) makes do with basically four locations plus a pointless car-chase, and saves Gigandet’s character for a glib “payback” third act, which at least looks vaguely military, if as heartless as the everything else.

But there’s little here that isn’t better experienced in a first-person-shooter video game, which at least has an excuse for being pretty much nuance-free and plotless. If you’re bored enough to add up the body count (26, I think), that’s a clue the movie isn’t working.

Rating: R, graphic violence, sexual situations, profanity

Cast: Jason Patric, Kesia Elwin, David DeLao, Guillermo Iván, Mauricio Mendoza and Cam Gigandet.

Credits: Directed by Willia Kaufman, scripted by Chad Law and Johnny Walters. A Saban Films release.

Running time: 1:31