When we first meet young Simon (Jonatan S. Wachter), he is in deep communion with his beloved oak tree and the magical shape-shifting clouds overhead. His hard-working father Erik (Stefan Godicke), a boat maker, does not appreciate his son's joy in imagination and reading. His mother Karin (Helen Sjoholm) usually takes Simon's side in these regular skirmishes with his dad. The year is 1939 and Sweden is preparing for an invasion from the Nazis.

At an upper-class grammar school, Simon makes friends with Isak (Karl Martin Eriksson), a Jewish boy whose mother's paranoia about being attacked by Nazis has traumatized him. When some bullies attack him, Simon surprises them and himself by knocking one of them to the ground with a punch his father taught him in an attempt to make him a man. Isak's wealthy father Reuben (Jan Josef Liefers) is a bookstore owner who sees in Simon a kindred spirit he can influence with his knowledge and love of culture.

When Isak's mother is put into a mental institution, he comes to live with Simon and his family. The boy gets interested in boat building and spends a lot of time with Erik. Reuben showers them with gifts and keeps at bay his attraction to Karin.

Lisa Ohlin directs this Swedish drama with a screenplay by Marnie Blok based on a novel by Marianne Fredrikksson. Part two takes place in 1945 when Simon has left behind his parents and his mysticism in order to savor the pleasures of the mind and the good life as epitomized by Reuben who has offered him a place to stay. His first foray into romance with a troubled concentration camp survivor Iza (Katharina Schuttler) ends badly. But even more unsettling is a family secret that rocks Simon's world.

Simon and The Oaks covers the various paths taken by a sensitive and smart boy and then young man in his quest for meaning.