National Treasure, Channel 4

Arresting elderly entertainers for historic sexual abuse now appears to be the primary function of the police, and here they are doing it again in Jack Thorne's new drama about veteran comic Paul Finchley.

Finchley is part of a much-loved double act with his partner Karl Jenkins (it seems strange that they named the latter after a popular contemporary Welsh composer, but he's played with carefully calculated ambivalence by Tim McInnerny), and Finchley's autumnal years suddenly turn to ashes when a pair of cops turn up at his door to inform him he's been accused of committing rape back in 1993.

With three more episodes to come, it's not yet clear whether National Treasure is going to be mainly concerned with Finchley's trial or whether it's a broader meditation on fame, morality and the passage of time. What stood out in episode one was Robbie Coltrane's thunderous performance as Finchley, a giant of a man hewn from decades of raw showbusiness, but now looking beached and lonely as his brilliant years pass into history. Director Marc Munden often filled the frame with the crags and fissures of Coltrane's face, which render most dialogue redundant, with Cristobal Tapia de Veer's hauntingly strange music lifting the production a few inches off the ground.

The opening sequence set up the scenario impeccably. Finchley was attending a grand showbiz awards ceremony to give a Lifetime Achievement gong to his partner Jenkins. Guest walk-ons by Robert Webb, Jimmy Carr and Frank Skinner, all hailing Finchley as a comedy icon who helped inspire their own careers, neatly put the "beloved entertainer" frame round him, while his prizegiving speech trod the bleeding edge between affection, respect and simmering resentment that Jenkins was getting the prize and not him. The notion that all the glittering prizes on earth can never be enough for insatiably ambitious, chronically insecure performers was slipped between the lines like an assassin's dagger.

In more ways than one, Jim seems to have fixed it for whole swathes of people ("they think I'm Jimmy fucking Savile," seethed Finchley, as his legal team prepared him for a second bout of police interrogation), but whether Finchley turns out to be guilty or not, National Treasure painfully evokes the misery and insecurity this kind of police inquiry inspires in its targets. Finchley's larger-than-life lawyer Jerome (Babou Ceesay) didn't bother to hide his fury ("cunts!") at the police's tactics of tipping off the press and publicly touting for more victims to come forward and join the "get Finchley" bandwagon.

Julie Walters is in the process of delivering another memorable turn as Finchley's wife Marie (pictured above), standing resolutely at his side but never able to forget her husband's endless catalogue of infidelities. Certainly, sainthood is not among his attributes. Having the cops ransack their home for evidence, ask her prurient questions and show her the pornography they've found on Finchley's phone has already sorely tested her resolve, and the suggestion that he might have committed multiple indecent acts with their teenage babysitter might be a whole bunch of last straws.

Also caught up in the debris field of Finchley's career is their daughter Danielle (or Dee), a recovering drug addict who can only interact with her father through a filter of rage and hostility. Andrea Riseborough (pictured above left) is throwing herself into the role with unsettling intensity.

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@SweetingAdam