Sign up for Weekday J and get the latest on what's happening in the Jewish Bay Area.

Full coverage of the 43rd San Francisco Jewish Film Festival

Lawrence Vincent was in the room four years ago when his son got the life-shattering news. “It’s a brain tumor,” the doctor told the 24-year-old, “and it’s terminal.” It was more than Vincent’s heart could handle — literally. He had a heart attack on the spot.

For both father and son, the ensuing years have brought anxiety, depression, uncertainty and moments of hope.

They’ve also led the older Vincent in an unexpected direction: to Judaism’s doorstep. Raised by Christian parents, Lawrence Vincent became interested in Judaism after his son’s diagnosis. Two years ago, he officially converted, and last year, he stood on the bimah reading from the Torah at his bar mitzvah as his son watched from the pews.

It’s a spiritual journey that very son, British filmmaker Kit Vincent, chronicles in his documentary “Red Herring,” which gets its West Coast premiere at this year’s San Francisco Jewish Film Festival. Both Vincents are expected to appear at the S.F. screening: Kit Vincent recently finished a course of radiation therapy, which appears to have had an impact, his dad said in a Zoom interview.

“His seizures are more under control, which is a very, very good sign,” Lawrence Vincent said. “As we speak, he’s in good shape.”

The lyrical, thought-provoking film is about many things: courage, unbreakable family bonds, the search for spiritual solace in times of groundlessness. Lawrence Vincent’s inquiry into Judaism began with an online course about the soul’s journey run by a Chabad rabbi in the U.S. In one scene, a kippah-wearing Vincent watches as the teacher describes the enduring connection between the living and those who have died.

“Your loved one, when they pass away, hasn’t gone to some faraway place,” the rabbi says. “It’s as if the whole family is together on the first floor of the house, and this loved one is in the same house with you, on the second floor.”

Lawrence Vincent, 63, served as chief academic officer at a college on England’s southern coast before retiring two years ago. He grew up in Leeds, home to a large Jewish population, and had a working philosophical knowledge of most religions. But he considered himself agnostic, even atheist, before his son’s diagnosis.

Now, he belongs to a Reform congregation whose rabbi has become a close friend. He celebrates Shabbat, has a bookcase full of Jewish-themed titles and often spends mornings studying the weekly Torah portion. In “Red Herring,” he celebrates Purim dressed as Albert Einstein. And he attends a public Hanukkah menorah lighting with his son and ex-wife, Kit’s mom Julie, a nurse who cares for dying patients but can’t fathom what it will be like to watch her own child die.

“There’s so much sensitivity in Judaism if you know where to look,” Lawrence Vincent said over Zoom. “It’s given me a soft, gentle space to go to whenever I need help.”

He’s needed help often as he and his family grapple with such agonizing unknowns.

“I don’t really think in weeks or months anymore,” the younger Vincent says in the film, which even goes close up on him having seizures. “I just kind of think in the windows of time between each scan. And I never really know whether it’s going to be this one or the next one when they tell me, ‘That’s it. Your time’s up.’”

A three-hour train ride separates Lawrence and Kit Vincent, but they see each other often. In one of the film’s many touching scenes, they sit by the water eating fish and chips and laughing, a father and son sharing an ordinary afternoon amid extraordinary circumstances. With their ruddy beards and shaved heads, they could almost pass as brothers.

Kit Vincent, a 2022 filmmaker in residence of SFJFF sponsor Jewish Film Institute, has been enthralled with cameras since childhood. His dad, despite being a highly private person, says he submitted fully to being filmed once it became clear how much it meant to his son to chronicle the family’s cancer journey. “Red Herring” has brought the pair closer than ever.

“I want to be able to give them something to watch when I’m not here, something to remember me by,” the young filmmaker says in the movie. “And I want them to know I was happy.”

“Red Herring”

(94 minutes) 2:45 p.m. Sunday, July 23 at Castro Theatre, 429 Castro St., S.F. Also 12:30 p.m. Friday, Aug. 4 at Piedmont Theatre, 4186 Piedmont Ave., Oakland.