Alfred Hitchcock is quoted on the cover as saying that "Psycho all came from Robert Bloch's book". I'd like to research that quote, partly because it seems uncharacteristic of that director to give such credit to an author and partly because Hitchcock's movie of Psycho, whose screenplay is credited to Joseph Stefano, makes a few improvements on the novel and some Hollywoodish changes.

The character of Norman Bates, for example, whose last name is an anagram of "beast" and whose first name signals his being neither normal nor man, is fat, middle-aged and balding and wears rimless glasses in the book. He is very unlike the young and good looking Anthony Perkins, who had been something of a teen idol at the time.

Another improvement is Bates's stuffed birds in the movie, which lend resonance to the name of the first murder victim, Crane (Mary in the book and Marion in the movie). In the book Bates's taxidermy is limited to one squirrel and, of course, one corpse.

The famous moment in which Norman tells Marion that "We all go a little mad sometimes" is "crazy" not "mad" in the book. This isn't significant but I think we're meant to remember that line a little later on when Sam Loomis is looking around the small town in which he lives.

We all go a little crazy with bloodlust once in a while, don't we? And a desire not to let go of our dead loved ones can be quite strong. And we keep coming up with more efficient ways to kill, from trench mortars to cannons to the orgy of armament deployed in World War II.

And all of this killing is balanced with the presence of the courthouse, the setting for all those Civil War veteran statues, thousands of them. Because we believe in law and order and peace, except when we don't.

It's Sunday morning, so presumably the square is empty because everybody is at church. We believe in "Thou shalt not kill", too, except when we don't.

This is an irony that Hitchcock would have appreciated but perhaps also would have found to be old hat. I don't remember it as being in the movie.

I'd always heard that Bloch had been prompted to write this book by the real-life horror of Ed Gein and in fact, when the story of Norman Bates hits the Fairvale newspapers and then the wire services, "Some of the write-ups compared it to the Gein affair up north, a few years back".

(Norman Bates's cellar contains syringes and several knives, so other murders are implied.)

The exploitation of the tragedy by journalists and politicians, for the advancement of their own careers, as well as by "rumor-mongers", is neatly noted.

But among mid-century crime fiction and thrillers, Psycho stands out as a solid entry, economical and flawless, an entirely satisfying work of craftsmanship whose subject matter was unusual for the time.

The first line is "Norman Bates heard the noise and a shock went through him".