The old saw is that you shouldn’t just a book by its cover. That’s a good rule of thumb when you’re dealing with people or if your presented with new ideas, but when it comes to actual books it’s kind of silly. Truth is a cover can often be someone’s first impression of a book and it can say several things about its contents, from the level of professionalism involved to the genre to particular aspects of the story or characters a reader might find intriguing.

Take, for example, the cover of The Water Road:

That cover, I hope, tells you several things. Most notably, that this is the first book in a trilogy, so it’s part of an epic story. The background image and script mark it as fantasy, but the crossed muskets mark it as a different kind of fantasy – this isn’t your traditional sword and sorcery story. Without reading word one, you’ve got some idea of what to expect going in.

I don’t always pay that much attention to covers as a reader, since I do most of my reading via Audible listening and I rarely have the full-sized book in my hand. Not that covers never make a difference – one of my recent reads, Johannes Cabal: Necromancer, I got purely because the cover on the shelf at the bookstore drew me in (it was darkly funny – highly recommended). So, anyway, the blurb usually controls, as it did for Autonomous, by Annalee Newitz. Here’s the first half:

Autonomous features a rakish female pharmaceutical pirate named Jack who traverses the world in her own submarine. A notorious anti-patent scientist who has styled herself as a Robin Hood heroine fighting to bring cheap drugs to the poor, Jack’s latest drug is leaving a trail of lethal overdoses across what used to be North America—a drug that compels people to become addicted to their work.

Pretty cool, huh? I loved the idea of a rogue drug maker slipping through the high seas like a 21st-century Captain Nemo. But here’s the cover for Autonomous:

Does that really match the blurb? It doesn’t and, turns out, for good reason. Autonomous (which is pretty good – I recommend it) really isn’t about Jack so much as it is the beings in her orbit, particularly the robots and other enhanced beings. The book is really about their place in the world and what it means to really be free (or not). Hence the title. Hence the mechanical arm in chains. Hence some of my disappointment with the book itself.

Which is to say that covers can be tricky things. We, as authors, want people to judge our books by them – judge them as worthy of picking up, of clicking on, of reading. But they’re also a first impression, something you only get one chance to make. The right cover is a high wire act, one that most of us aren’t comfortable performing without a net.