The complex tale is split into three different time periods, beginning in the 16th century, when a conquistador named Tomas (Hugh Jackman) strives to find the Tree of Life.

The second part finds Jackman playing a Buddha-like character who zips through outer space and dreams of a woman named Izzi (Rachel Weisz).

And the third part, which consumes most of the film, is set in the present day and sees Jackman playing a doctor named Tommy, who is married to the terminally ill Izzi. Tommy strives to find a cure for Izzi's brain tumour, and makes some progress after experimenting on a monkey with a substance discovered in a tree in South America. Meanwhile, Izzi has been writing a book that she calls The Fountain, but has left the final chapter for Tommy to write.

The film makes for uneasy and sometimes confusing viewing, but will find its audience among intrepid souls who are prepared to immerse themselves in Aronofsky's peculiar, daring, and thoughtful cinematic universe.