Throughout the divided format of “Tabu,” we are treated to shots of crocodiles. You are free to fill in your own meaning for this reptile visitor, but one thing it reminds us of: However much civilization there appears to be, wildness is lurking about. Or within.

So it proves for the stories we see in this beguiling Portuguese film. A jungle-movie prologue, featuring a colonial-era man consumed by a crocodile, is being watched by a present-day Lisbon woman (Teresa Madruga).

She’s a little bored with modern urban life, and is dragged into tending to an elderly neighbor named Aurora, whose health is deteriorating. Aurora invokes the name of a man from 50 years earlier, Ventura, and when he arrives on the scene, he has quite a story to tell.

We’ve been watching this modern tale for 45 minutes or so, but when the man begins to narrate his story, everything shifts. We’re in Africa, early 1960s, the sunset of the colonial period.

Ventura (played now by Carloto Cotta) recalls arriving at the coffee farm owned by Aurora (Ana Moreira) and her husband. A tale of lust and passion follows.

There isn’t much surprising in the plot, although a final twist about the political realities of this African country is well-judged. No, the novel thing about “Tabu” is how the movie comes to us: The somewhat humdrum modern-day scenes followed by the movie-movie drama of the flashback.

Plus, it’s all in black-and-white, and the African scenes (shot in Mozambique) have no dialogue. It took me a while to actually realize that this segment was essentially a silent film, because we do have Ventura’s voiceover narration, plus some pop songs to represent the era.

This curious and unexpectedly intoxicating concoction comes from director Miguel Gomes, who wants us to take our regular movie-watching habits and hold them up to scrutiny. Or maybe scrutinize our memories of our own lives and the way we can’t help but turn our old experiences into movies, more romantic than they really were.

Gomes doesn’t create films that made A-B-C sense, and he has admitted that when he shoots, “I proceed like a collector not knowing what kind of collection I’m making, but I’m collecting something.”

Maybe because of that, “Tabu” feels like a search, not a definitive statement. You’re on safari, and the movie is the journey, and you’d best keep an eye out for crocodiles along the way.

“Tabu” HHH1/2

Portuguese filmmaker Miguel Gomes takes us to modern Lisbon, where an elderly man recalls an unexpectedly romantic tale of ’60s colonial Africa. Shot in black and white, the film’s mysterious meaning plays with how we turn our own memories into romantic movies. In Portuguese, with English subtitles.

Rated: Not rated; probably PG-13 for subject matter.

Showing: Northwest Film Forum.