A book

Waterstone's is always good for a browse.   I'm not buying so many physical books these days; I tend to buy what I would describe as disposable books in electronic form, but reference books I still buy the paper version.

The graphic novels are a case in point.   They don't really work well as electronics.   They're similar in some ways to a film adaptation of a book, they offer a new perspective on the story, and rely on a visual artist's impression of the images, rather than the reader's own imagination.  Some are more successful than others.  This one is a good one.