In an early scene in The Boy with the Topknot, the new film from BBC2, Anupam Kher is shown poring eagerly over a newspaper, as his son, a flashy journalist from London, comes to visit their home in Wolverhampton. Father and son share the briefest greeting before the son hugs the mother. For a split second, the viewer may place the difference in effusiveness to gender dynamics, but a closer watch suggests otherwise.

Sathnam Sanghera’s memoir The Boy with the Topknot: A Memoir of Love, Secrets and Lies in Wolverhampton about growing up Sikh in Britain appeared in 2008 – a book so moving and profound that it won multiple prizes in the year of its release. It has now been adapted into a television film with Kher playing the father, Deepti Naval the mother and Sacha Dhawan, a promising young British actor, playing Sathnam.

The awkwardness between father and son is subsequently explained as mental illness. Sathnam’s father and sister suffer from schizophrenia, a fact that he was unaware of even into his twenties. The visit that begins the film sets in motion this discovery and its ramifications on Sathnam’s views of family and self.

The Boy with the Topknot.

The Sangheras moved to Britain in the 1960s and Sathnam, the youngest of four children, was born there. He studied English at Cambridge, growing up to be the kind of super-achiever whose education puts him at odds, educationally and emotionally, with his family.

The first break came at 14, when he shed the topknot. Subsequently, he moved out, built a life in London interviewing global celebrities, and found love with a white woman. The film moves back and forth between these twin strands: Sathnam’s inability to blend his life with his past and the past’s relentless march into the present.

Unable to tell his mother about his romantic partner, Sathnam starts digging up about his father’s illness. As he discovers more and more – his father has never worked a traditional job; his lack of aggression, an outcome of medication, masks his earlier violent tendencies – his shame at shutting his family out grows in proportion.

From the man whose frustration at not being able to tell his family about his girlfriend is dipped in condescension, Sathnam transforms into someone who realises the flimsy nature of his dilemmas. Dhawan captures this transformation well, his pleasing personality more effective as the guilt-ridden Sathnam than the brash avatar of the film’s beginning.

But the real star of the film is Naval, who plays the long-suffering wife. When Sathnam probes her to reveal more about her past with his dad, she shoos him away, first gently and then purposefully. Sathnam ultimately gets the story from another source but the viewer, guided by Naval’s silences, is able to guess at its contours long before the fact.

Due to the demands of the medium, the film edits out a lot of the material from the book. But it keeps the original’s spirit intact. By the end, Sathnam has reached a modicum of reconciliation, not just with his family’s past but his own, cognisant of how his every success is mapped to the struggles, failures and, ultimately, triumphs of those who came before him.

Sacha Dhawan on playing Sathnam Sanghera.