Well THAT was different.

For the first half of “Allied,” I was immersed in a taut, tense World War II thriller that played like a mash-up of “Casablanca” and “Inglourious Basterds,” with Brad Pitt’s Canadian intelligence officer Max Vatan and Marion Cotillard’s French Resistance fighter Marianne Beausejour (such names!) teaming up for an elaborate undercover mission involving a staged marriage, hot-and-heavy sex in their car while a sandstorm whirled around them and a seriously badass takedown of a room filled with Nazis.

Next thing I knew, the staged marriage had become a real thing, and Max’s lesbian sister Bridget (Lizzy Caplan) was talking about how she’s going to miss the war because during the war, anything goes sexually (who knew?!) and Marianne was giving birth in a London hospital during a bombing raid, and then Max and Marianne and their cherub were living a relatively idyllic life in London even though the war was still raging — and we haven’t even gotten to the picnic Max and Marianne hold on their front lawn, just yards away from a downed German bomber still smoldering and with dead German pilots still presumably inside the wreckage.

Oh wait, don’t let me forget about the one-armed drunk who holds the key to a life-and-death mystery!

The highs are so impressive and the lows are so … weird in “Allied,” I wouldn’t be surprised if this is that rare film that lands on some critics’ Top 10 lists while others find a place for it in their rankings of the worst movies of the year.

I’m gonna split it down the middle with a qualified recommendation. Directed by the innovative, sure-handed veteran Robert Zemeckis (the “Back to the Future” movies, “Forrest Gump,” “Castaway,” “The Polar Express”) and featuring two beautiful and quite talented actors hamming it up like nobody’s business, “Allied” is reportedly inspired by the true story of a British spy ordered to kill his own wife when she is suspected of being a double agent — but it feels more like schmaltzy if entertaining pure fiction than anything resembling a fact-based World War II drama.

The 52-year-old Pitt, sporting longish hair hardly in keeping with early 1940s military style, and with a distractingly unlined face — movie magic, or good genes? — that makes him look like he’s in his mid-30s, is Max, an intelligence officer who parachutes into the North African desert and is picked up by a driver who takes him to Casablanca. (The timeline is maybe a year or so after the events of “Casablanca.” No word on whether Bogie is now running another version of Rick’s Café or perhaps an altogether new establishment.)

On the way to Casablanca, Max opens his cool briefcase, which contains new IDs, cash, a change of clothes and guns. (This is the kind of movie where Max shuffles through the IDs and flips the cash through his fingers and checks out the guns just for our benefit, so we know he’s a super-spy kind of guy.)

I loved the Casablanca scenes. Cotillard, looking like an old-school movie star, is a stunner as Marianne, who commands the room with her wit, her style and her ability to make everyone around her feel special. Marianne has managed to gain the trust of the highest-ranking German officers and their powerful sympathizers. The arrival of her “Parisian husband” is met with only slight skepticism.

Marianne schools Max on his French accent — she says he sounds like he’s from Quebec, not Paris — and the manner in which a husband and wife would interact after not having seen each other for a very long time. She warns him against falling in love with her, as that could get them both killed.

So of course they proceed to fall in love.

The mission in Casablanca makes for half a good movie. It’s when the story shifts to London, and the weird hybrid of domestic drama and wartime intrigue, that “Allied” sometimes stretches credulity and veers close to unintentional humor, e.g., an encounter in a veterans’ hospital between Max and an old buddy (Matthew Goode) who shields the nature of his injuries until he dramatically swivels his face to shock Max — and us — with his tragic disfigurement. Talk about over the top.

As played by Pitt, the supposedly lethal and revered intelligence officer Max is kinda dim at times, not to mention prone to little temper tantrums, e.g., kicking over a chair when he gets some bad news from a superior officer.

Cotillard’s Marianne is a woman of mystery. Is she really an agent of the French, or is it possible she’s a German spy who has taken on the identity of a French woman and is so committed to Hitler’s cause she would marry an Allied officer and GIVE BIRTH TO HIS CHILD, all in the name of intercepting top secret information?

More than a decade after “Mr. and Mrs. Smith,” Brad Pitt stars in another thriller about married assassins who just might have to kill one another. What are the odds?

I’ll leave it to the relationship journalists to dissect how these two films wound up as professional bookends marking for the romantic union of Mr. Pitt and Ms. Jolie. We are here to talk about the movie, and the movie is entertaining, perhaps more so if you’re at one of those establishments where they allow you to bring a generous pour of wine into the theater.

★★★

Paramount Pictures presents a film directed by Robert Zemeckis and written by Steven Knight. Rated R (for violence, some sexuality/nudity, language and brief drug use). Running time: 124 minutes. Opens Friday at local theaters.