ZAC  Efron has come some way since his Disney Channel days. Having devoted the best part of a decade to ropey bromantic comedies, the one time High School Musical heartthrob took a sharp left turn for the 2019 Netflix hit Extremely Wicked, Shockingly Evil and Vile, in which he played serial killer Ted Bundy.

A survival thriller, sci-fi horror and war comedy later and he’s back on screens for Sean Durkin’s The Iron Claw. While the likes of Baywatch, Bad Neighbours and Dirty Grandpa might have set a low bar, it’s easily Efron’s best work to date.

The film tells the true story of the right knit Von Erich family and the brothers who changed the face of American professional wrestling in the early 1980s. Outside the ring, The Iron Claw explores the role of the brothers’ domineering father in their rise to sporting immortality.

Of Fritz Von Erich’s six sons, all but one took to the ring as a professional wrestler. That was his first born, Jack, who died in a tragic accident, aged just six, ostensibly due to a family curse inherited from his grandmother. Only one of Fritz’s sons would out live him.

The titular “iron claw” is, then, threefold. It was Fritz Von Erich’s signature move in his fifties heyday, a vice like facial grip to floor one’s opponent. For Durkin, it serves also as a metaphor for Fritz’s grip on the lives of his sons. Moreover, it alludes to the hold of the ‘Von Erich curse’ over all in his line. Paranoia proves a central focus in a film that becomes increasingly bleak from year to year.

Efron dominates here as Kevin, the eldest of the wrestling quintet. Jeremy Allen White is Kerry, while Harris Dickinson plays David and newcomer Stanley Simons is Mike, a youngster pushed from his musical inclinations to his father’s family enterprise. As for Fritz, he’s played by Fight Club’s Holt McCallany.

A final brother, Chris, is omitted completely from the film. Presumably this is for the benefit of allowing the other brothers’ stories room to breathe but it feels odd nonetheless. His was a bleak and desperately short life.

Such is the nature of the film. There is warmth in the fraternal relationships - and a nice turn from Lily James - but it’s terribly emotional stuff. Pressure is a cruel burden.