A boy on a black bicycle slushes by a long line of gray-clad soldiers, pedestrians and refugees on a snowy dike-top road.

It’s January of 1945, “Winter in Wartime,” and nobody has gasoline but the Germans, and the Germans are an occupying army on its last legs. The Dutch are hanging on and hanging back, hoping to keep their heads down long enough for the war to be over and the Nazis booted out.

That’s what the mayor (Raymond Thiry) of a small town in occupied Holland hopes to do. He is all smiles, backslapping the German troops, glad-handing the officers, trying to talk them out of arresting this neighbor or that one.

But his teenage son Michiel (Martijn Lakemeier) seethes as he watches this. He and a pal collect war souvenirs, sneaking in under the noses of the Nazis to cadge items from a crashed bomber the Germans are supposedly guarding. Only the fact that Michiel is the mayor’s son saves him. But the ungrateful kid only looks up to is his Uncle Ben (Yorick van Wageningen), a Resistance fighter who takes refuge in their house.

Michiel is about to have his chance to be a hero. Circumstances make the kid the only living person in town who knows about an injured British airman (Jamie Campbell Bower) from that very bomber crash. Jack  (Bower) becomes Michiel’s special project — getting him food, getting his wounds cared for and getting him out. Michiel will show just how good he is at keeping a secret, just how much smarter he is than his family or those pesky Germans.

But the deeper the kid gets into this deadly game, the more in over his head he realizes he is.

The situation isn’t the most original, and co-writer/director Martin Koolhoven can’t keep the melodramatic possibilities in “Winter in Wartime” at bay for long. The flyer is wounded, Michiel’s sister is a 20ish nurse, so there’s one problem solved and maybe another cropping up. The kid is conflicted — one minute the Germans are cruel and callous, the next minute compassionate and considerate. We also aren’t given enough doubts about the mayor/father’s true motives and character. And side stories — are they hiding Jews in his house? Are the neighbors?  — are left unexplored and unexplained.

But it’s a sturdy World War II yarn, with harrowing and heart-breaking moments sprinkled throughout. The look of the movie is pristine, lives of privation made more stark with each fresh fall of snow. And little touches give it a lift. Michiel’s realization that he’s leaving childhood behind comes on that very bicycle. He takes the playing card out of the spokes, which like millions of children he’d used to simulate the sound of a motor. Now, lives are at stake and he needs stealth.

“Winter in Wartime” begins rather better than it ends — contrivances pile up like wooden Dutch shoes in the third act. But it’s still a most involving and touching coming of age tale set in a time and place when childhood was a luxury few families or nations could afford.

MPAA rating: R for some language.

Cast: Martijn Lakemeier, Jamie Campbell Bower, Melody Klaver, Yorick van Wageningen

Credits: Directed by Martin Koolhoven. A Sony Pictures Classics release. Running time: 1:41.