In 2008, during his last year of graduate school at New York University, William D. Caballero pitched a film about his Puerto Rican family to the professor of his documentary production course. His pitch was rejected. She told him no one would want to watch a film about his family.
“I’m usually the type of person who does whatever the teacher wants, but in this case, I was like, ‘No. You don’t know my family well, and if I want to do this project, I will.’ And she gave me a B-plus for the class out of spite,” Caballero recalled.
But it was Caballero who had the last laugh.
That first documentary, “American Dreams Deferred,” was a launchpad to more experimental films weaving animation with live action, often depicting family members as lovingly designed, 3D-printed miniatures.
The short documentaries “Victor & Isolina,” which animated his grandparents’ bickering about their tumultuous relationship, and “Chilly & Milly,” which explored the difficulties of navigating his father’s diabetes and kidney failure, premiered at the 2017 and 2022 Sundance Film Festivals, respectively. Caballero has returned to the festival for its final year in Park City with his feature documentary, “TheyDream.”
Through “TheyDream,” Caballero and his mother, Milly, use the creative process to navigate grief over the deaths of Caballero’s father, grandparents and dog.
“TheyDream” is at once a scrapbook and a making-of documentary as viewers watch Caballero and Milly create the film they are watching. Caballero composites home video footage and audio-recorded conversations with a variety of animation techniques, including miniature, hand-drawn 2D and 3D motion capture.
“I’m playing with all of these puzzle pieces of archival footage from throughout my life and rearranging them in a way that transforms them into ‘TheyDream,’ into this really kaleidoscopic project that examines not just my life, but important people who are part of my life as well,” Caballero explained.
He said the easy answer to the question of how long he’s worked on the film is four years, but in reality, it’s closer to his entire life. He’s been documenting his family for 18 years, a practice that he recommends to everyone, not just filmmakers.
“The best thing to do, rather than shoving an entire camera into your family members’ faces or having a huge crew show up … is to say, … ‘I’m just going to press record on my iPhone, put it down. Let’s just talk,’” he said. “Maybe you won’t make art with it, but you’ll have it. … I constantly tell people, ‘If someone matters to you and they mean a lot, get their stories because there’s going to be one day when they’re not around.”

With the conversations Cabellero recorded, he and his mother could use motion capture to embody their deceased loved ones, acting out their mannerisms over the audio and using animation to bring them back to life.
It was a process that brought up complicated emotions, but Milly was completely on board.
“If she ever had a problem, I could always be like, ‘OK. Cut the camera. Mom, let’s talk. How do you feel?’” Caballero said. “But there was very little of that. I think that we were able to really create something that is very authentic.”
Through “TheyDream,” Caballero wanted to give his mother the same access to creativity that helped him as a child. Learning to play violin in public school was Caballero’s escape from the trailer he grew up in, in his grandmother’s backyard in North Carolina. He called it a gateway drug to animation, dance and other forms of art.
For Caballero, one of the greatest challenges of making “TheyDream” was reigning in his own creativity.
“I storyboard (scenes) really safe at first. And then I’m like, ‘Still not there yet. What if I added this ingredient, that ingredient?’ And so, I add more ingredients to the cake, and then I’m like, ‘I have no idea how I’m going to cook this,’” he joked.
That was where his talented team of fellow animators came in, always game to try unfamiliar methods or advise Caballero how to bring his ideas to screen.

Caballero wore many hats in the creation of the film, but he was in some ways a character, too. The fact that he’s exposing some of his most vulnerable moments to the world isn’t lost on him, but he was inspired by artists before him, like Pyotr Ilyich Tchaikovsky and Frida Kahlo, who did the same.
“TheyDream” isn’t quite an exposé of every tidbit of family lore, but it does depict strained relationships and wrenching grief with naked honesty.
“I wanted this to be a film that wasn’t just the promotion of happy, tender-hearted moments with family,” Caballero said. “There are lots of moments in the film that are visceral, that are acidic, that are honest, that are painful. And I think that’s life.”
He added that depicting those difficult moments with honesty creates a greater bridge between viewer and filmmaker. There are “universalities” between people that are realized through film.
“I was born Latino. I was born pretty much in poverty, (with) two disabled parents. … Society, it felt like, had no interest in my story,” he said. “But I fought against that my entire life, to showcase my stories of my family are indicative of the American experience. And if we’re going through this, you’re probably going through this, too.”
“TheyDream” premiered at 2:45 p.m. on Jan. 23 at the Library Center Theatre.
Learn more and reserve tickets at festival.sundance.org.

‘TheyDream’ in-person screenings
- 2:45 p.m., Jan. 23, Library Center Theatre
- 10:20 a.m., Jan. 24, Megaplex Redstone 3
- 12:00 p.m., Jan. 25, Broadway Centre Cinemas 6
- 10:00 a.m., Jan. 29, Holiday Village Cinemas 2
- 3:15 p.m., Jan. 31, The Yarrow Theatre
