An intensely moving personal essay about living in the shadow of illness, Sea in the Blood explores two of Fung's closest relationships — with his late sister Nan, who died in 1977 of a rare blood disorder called thalassemia (which literally means "sea in the blood"), and with his lifelong lover, Tim, who has been living with HIV since 1980.

The film begins with the soothing sound of gurgling water and an ethereal image of Richard and Tim swimming between each other's legs as veiny patterns of light dance across their skin. The sea is the central metaphor, an image Fung explores from different angles — some poetic, some medical. But Nan's death is the emotional epicentre. Despite an age difference of six years, Richard and Nan are inseparable as children in Trinidad. They drape fake pearls around their necks and secretly read Mao Tse-tung together. Years later when Nan lies dying in Toronto, Richard is travelling with Tim in South Asia. Believing that his parents are trying to lure him back to Toronto out of disapproval of his relationship, he is left to grapple with the fact of his absence at the crucial hour.

Two decades later, Fung shapes different elements — historical footage, family photos, old letters, travel slides, interviews, home movies, subtitles, cartoons — into a belated elegy to his sister. In contrast to some of Fung's more pedagogical tapes, Sea in the Blood is a highly meditative work. The return to the same image of a rose-coloured sea reveals a sense of endless drifting and suggests a vast space of unknowing. (Tim's HIV diagnosis three years after Nan's death is the shadow text to the narrative.) The final image is taken from an angle that renders the breaking of surface, as Tim and Richard slip from water into open air. The story remains, finally, unfinished, but as John Berger once wrote, "Never again will a single story be told as though it were the only one."