A deeply unsettling children’s teatime drama, both the grown-up themes and the melancholic timbre of The Intruder are far removed from the usual lightweight preoccupations of 1970s kids’ TV serials.

Adapted from the novel by John Rowe Townsend, the series’ bleak setting is an isolated village on an outcrop off the British coastline where tidal surges cut off the residents from the mainland. Helping visitors navigate the treacherous crossing is Arnold Haithwaite, a ‘sand pilot’ whose family runs the local shop. But the aged man he calls father harbours a secret about Arthur’s parentage that he refuses to divulge. The young man’s anxiety about his real nature is heightened by the arrival of a mysterious stranger who claims he shares more than the family name with the young Haithwaite. Amongst a small but committed cast, Milton Johns is singularly impressive as the creepy and disturbing interloper.

The Intruder is sombre, downbeat and sporadically alarming. Its plot wrestles with issues of identity, attachment, family and class, generational conflict and adolescent longing. There’s precious little humour and lots of ill-tempered exchanges between characters. But it remains a strangely compelling watch, particularly in its determination to keep its young audience guessing about the place’s buried secrets, and in the way its atmospheric filming locations are framed on screen. As a niche provider, tight budgets often mean that Network’s releases have to remain vanilla. This Blu-ray is better served, offering idiosyncratic solo episode commentaries from writer Tim Worthington; a sit-down with Townsend from a 1972 episode of Granada’s Writers’ Gallery; a new interview with actor Simon Fisher Turner; and a typically comprehensive booklet from renowned TV historian Andrew Pixley.

THE INTRUDER is available on Blu-Ray from Network on OCTOBER 17th