See it run across the rooftops of the world. See it leap the divides of years and decades. See it pursue the ruthless, swift-heeled mastermind known as “Citizen” Kane. See it slip and tumble – it takes only a careless moment – and cling to the high guttering while the downward view seems to concertina beneath. See it survive, recover and live to continue the chase.

“It” – what else? – is Alfred Hitchcock’s Vertigo. The cinema’s greatest romantic thriller is 50 years old this summer. Many happy returns to a masterpiece, and there surely will be. Vertigo is now a perennial, number two in almost every critics’ poll of great all-time movies and hotly pursuing Kane for the top spot.