Ace Double: D-Series

Ace published their "double" books for a 21 year span in a number of different lettered series: D, F, G, H, and M plus one numbered series. The books were called "doubles" because they were 2 short works combined into a single volume with 2 covers that were rotated 180 degrees from each other so you can flip them vertically to see the other book. These works were single titles that were either short novella length stories or longer, often abridged, stories. The series run contains mainstream mystery, adventure, and western stories mixed throughout. In order for us to display both covers we have created animated .gif images that flip between the 2 sides.