Joss Whedon's short-lived sci-fi series Firefly has been off the air for seven years, and its feature-film follow-up, Serenity, has been out for four, but the pain of the show's passing still smarts. While Serenity provided much-needed closure, it only made us love/miss Firefly all the more, so when we saw that a behind-the-scenes book of photos, props, artwork and original stories was coming out, we made sure to get ahold of it. Firefly: Still Flying comes out on May 25 from Titan Books, but we've already read it cover to cover. And you know what? We learned some stuff we didn't know about one of our favorite shows ever. Prepare for information upload!