Christopher Gray makes the link between the last episode of Endeavour and former Liberal leader Cyril Smith

Beyond belief? Perhaps. Young boys in an institution being thrashed by an old pervert and this sanctioned — well, certainly overlooked — by those with responsibility to protect them from harm.

Sunday night’s closing episode of ITV’s Endeavour is what I am referring to, although some readers will doubtless have thought at once of the revelations concerning the fat paedophile Cyril Smith.

Actually, for some people — myself included — they weren’t revelations at all. His strange habits were revealed to the world though exposure in Private Eye as long ago as 1979.

Incredibly (literally so) nobody in the Liberal Party and its successor the Liberal Democrats appears to have been aware of Smith’s tastes. Actually, not quite nobody. A spokesperson for David Steele revealed the former Liberal leader’s knowledge of the matter. Steele said — in a sentence that will come to haunt him as the scandal grows (and it will) — “All he seems to have done is spank a few bare bottoms.”

Returning to matters more seemly, it was good to see at the close of Endeavour through the detective’s . . . er, predicament, that the door was clearly being kept open (an inapt metaphor in the circumstances) for a new series of adventures.

This is great news. As one fully operational in 1966, when the action is set, I find the recreation of the period to be faultless. It seems an odd coincidence to me, though, that Morse’s boss, DI Fred Thursday, shares his highly unusual surname with the title character of another television series that began in the very same year. This was Mrs Thursday, starring Kathleen Harrison as a charwoman turned business brain. Perhaps she was Fred’s mum . . .