"Harry Potter: The Exhibition" is enriched by meticulous detail. Left, a host at the entrance; movie memorabilia and exhibit visitors, below. Photographs by Robert Caplin for The New York Times

Before visiting "Harry Potter: The Exhibition" at Discovery Times Square, I mistakenly assumed that the real point of this 1,300-square-meter display of movie sets, costumes and props would come at the end, where Potterphiles can purchase $44.99 replicas of Albus Dumbledore's magic wand or $49.99 replicas of Gryffindor's school tie.

There is a strong commercial element here; adult admission is a hefty $25. The exhibition was created by Global Experience Specialists, in conjunction with Warner Brothers Consumer Products. About a million visitors have seen it since 2009, when it began touring in Chicago and Boston, and then Toronto and Seattle in 2010. After September 5 it will travel beyond North America.

But the exhibit is quite bewitching, and commerce is just a small part of it. It takes its subject seriously, demonstrating how an imagined world is brought to life by meticulous attention to detail. It makes the universe of J.R.R. Rowling's books (and the movies made from them) palpably vivid.

Visitors begin in a gallery where an actor invites volunteers to try on the Sorting Hat, which directs them to the wizarding school of Hogwarts. Accompanied by video montages from the movies, we are led past teachers - villainous and eccentric - and magical objects.

Eventually we make our way to where the ghastly Dark Forces congregate. There were the fizzing whizzbee candies from Hogsmeade, "Cram It!" guides for school finals and a glimpse of Dobby the house-elf.

But these props are not just reminders of something seen more potently and in wider context in the movies.

Instead, it becomes clear that the movies work so well because no object really is just a prop. Everything is thoroughly imagined.

The antic narcissism of Professor Gilderoy Lockhart (played by Kenneth Branagh) is seen in his book jackets, his classroom tests and his gold ruffled necktie. Professor Lupin's intense traditionalism is reflected in his old-fashioned gramophone records; Ron's clothing is clearly inherited from his brothers.

Nothing is too small to notice; the imagined world, following the example set by Ms. Rowling, is saturated with details.

And there is something else. The Harry Potter films and books are suffused with a reverence for the past.

The books displayed here are designed to look like volumes from the early 20th century (with some, of course, even more ancient). Adult clothing styles barely reach beyond the Edwardian era. Hogwarts is haunted by traditions and Gothic details. The school uniforms could be worn by the children in C. S. Lewis's war-darkened England.

This is a world full of things past. The movies' creators are exquisitely attuned to that aspect of the novels, along with an almost modern celebration of multicultural possibilities. Ms. Rowling looks forward and backward simultaneously. The heroic figures are the hybrids, the orphaned, the outcast, the eccentrics, the true inheritors of a great tradition. The villains are the pure-blooded absolutists who threaten to overturn it all.

This places the Potter tales right at the center of the 20th-century fantasy tradition that grew out of the work of two British writers around World War II: Lewis and J.R.R. Tolkien. It also gives the series an almost touching nostalgia for a world about to be destroyed.

The show pays tribute to a lost world, just as the film series is about to come to an end. In a desire to hold off the apocalypse, I was almost inspired to buy a wand.