John Joseph Adams is fairly well known in science fiction, fantasy, and speculative fiction literary communities for his anthologies. Several are on my ever-growing to-read list, but when I first heard about Other Worlds Than These: Stories of Parallel Worlds, it made the top of my list. I was not disappointed. Difficult to classify in any specific genre due to the sheer variety of writing, Adams’ anthology cannot be dismissed as easy reading—no surprise as it is 550 pages, including 31 short stories. With heavy-hitting names like Joyce Carol Oates, Stephen King, Ursula K. LeGuin, George R.R. Martin, and Orson Scott Card, among the many others, the diverse fiction offering requires a reader’s full attention—and occasional breaks between stories to allow them to sink in more fully.

Ideas surrounding parallel worlds are incredibly varied and oft toyed with in fiction. Featured multiple times in Star Trek, Doctor Who, and other science-fiction classics, the idea of other universes parallel to our own with slight or drastic differences captures the imagination. Sliders, notably, focused entirely on travel between parallel worlds. Neil deGrasse Tyson even briefly discussed the idea of alternate universes win his new series, Cosmos. Often connected to the idea of free will—that the choices we make determine our destiny and the destiny of the universe—parallel worlds make for fascinating reading.

In Other Worlds Than These, the drift between worlds can be as simple as stepping through a door, as with Oates’ “The Rose Wall” or David Barr Kirtley’s “The Ontological Factor.” Or it can be complex, requiring engineers and devices, as with Alastair Reynolds’ “Signal to Noise.” Each story constructs its own idea of how the move between worlds might work, and not all authors choose to reveal the method to the reader, leaving it mysterious and magical. The stories represent multiple genres, including dark fantasy, science fiction, and even experimental—Mercurio D. Rivera, in “Dear Annabehls,” writes in a “Dear Abby”-esque letter style.

One of my personal favorites likely spawns from my early introduction to Bruce Coville’s Magic Shop series as a child. “Impossible Dreams,” by Tim Pratt involves a shop which exists only at intervals in our universe. The protagonist, a movie buff, stumbles upon a previously unknown video rental shop and at first takes the selection to be a joke—movies never heard of, or altered in some way. The shop disappears when he runs home for money. Upon subsequent encounters, he slowly realizes the shop, and its pretty employee, typically reside in a parallel world.

Jeff VanderMeer tackles recent history, with a variation, in “The Goat Variations.” An alternate universe version of George W. Bush looks into a top-secret machine built from schematics provided by an imprisoned psychic. As he sits in front of the school children on September 11, the infection of the machine smashes the barriers between his mind and those of all other versions of him in other worlds, forcing him to experience their lives as well as his own.

Several stories tackle childhood fantasies versus reality, the parallel worlds children travel to in their imaginations and dreams. The main character in Carrie Vaughn’s “Of Swords and Horses,” a mother, copes with the sudden and unexplained disappearance of her daughter, and encounters the barrier between worlds. In Seanan McGuire’s “Crystal Halloway and the Forgotten Passage,” a teenager learns what cleaves the worlds of childhood and adulthood, the hard way.

McGuire and Vaughn’s stories represent my connection with this book, what I consider an essential truth; whether we read, watch, or write fiction, often it involves escaping into a world which differs from our own. Since I was a child, escape has been my impetus for reading. Other Worlds Than These explores the idea of parallel worlds implicitly and explicitly, depending on the story, toying with the very thing which hooks us into fiction. The sheer variety of genres represented mirrors the possibilities we can fall into whenever we open a book or turn on the television.