The deeply, darkly mysterious Israeli documentary “Stefan Braun” is the closest we are ever likely to get to Mediterranean Gothic.

This fascinating and ultimately haunting film introduces us to elderly Eliezer Rath, who spends his days and nights alone with the memories and mementos of the love of his life. Rath is comforted, and perhaps a little tormented, by the memory of his partner of 39 years, the deceased Stefan Braun.

Braun owned a high-end fur salon in Tel Aviv for decades, but he wasn’t a businessman so much as a designer, impresario and benign tyrant who inspired total devotion. He was also an active gay man at a time when homosexuality was a crime and a certain discretion was advised, even if you were wealthy, handsome and established enough to live by your own rules.

Braun’s vibrant personality shines through in the trove of photographs and home movies Rath included in the film. However, it’s not what we see that makes “Stefan Braun” so gripping but what we discern, imagine and extrapolate about Braun and Rath’s fraught relationship.

“Stefan Braun” has its U.S. television premiere 9 p.m. June 23 on the Sundance Channel. Airing during Gay Pride Month, the one-hour film delivers a sliver of history — who knew there was a thriving fur boutique in mid-century Tel Aviv? — and pathos well worth any viewer’s time.

It’s also full of small delights, from the archival footage of fashionable Allenby Street (where the Stefan Braun salon was located) to the wonderful (though superfluous) shots of the launch of the Theodor Herzl ship in 1957.

Before World War II, European immigrants brought their furs with them to pre-state Israel, apparently unaware of their new home’s climate. Although outside the scope of the film, this detail doubles as a subtle reminder that those who were able to get out of Germany in the 1930s were overwhelmingly people of means.

By the ’50s, when he picked up a young waiter named Eliezer Rath at the Ramat Aviv Hotel, the confident Braun had established a top-drawer reputation and a loyal clientele among wealthy Israelis and tourists.

From most accounts, the glamorous Braun and the ordinary-looking Rath were in love and committed to each other. But the charismatic Braun never deprived himself of the company of an attractive young man. Furthermore, he often treated Rath as a servant more than a partner. One might say that Braun paid the piper, and he called the tune.

Nobody can know the absolute truth about other people’s relationships, and much of the pleasure and ephemeral sadness of “Stefan Braun” is listening to the testimonies of clients, friends and relatives and sussing out the inner workings of Rath and Braun’s lengthy liaison.

Filmmakers Itamar Alkalay and Nir Shenhav enjoy doling out revelations and shifting tones. “Stefan Braun” is alternately irreverent and bluesy, wistful and breezy, nostalgic and tinged with yearning and bitterness.

When Braun died in 1990, his will left everything to Rath. This fact is not exposed until late in the film, along with the revelation that the furrier’s family — members of which have been interviewed throughout the film — was stunned and began a legal battle that lasted four years and, inevitably, destroyed their relationship with Rath.

Was the suit about money? Or, even though Braun was out to his family, did they feel betrayed and hurt? For his part, Rath is convinced he’s owed for giving 39 years of his life to waiting on his lover.

After patiently and carefully bringing into focus the picture of Braun and Rath’s life together, the filmmakers have intentionally blurred it again. They leave us in an unusually delicate place, pondering the unfathomable depths of human relationship.

“Stefan Braun” has its U.S. television premiere 9 p.m. June 23 on the Sundance Channel.