It's hard getting over a cancelled TV series, but Dark Horse is making it that much less difficult by introducing new adult coloring books for cult sci-fi/fantasy properties "Serenity" and "Avatar: The Last Airbender." On sale this fall, both books come printed on thick, heavyweight 10 x 10-inch pages, for the affordable price of $14.99 USD.

Illustrated by Jed Henry, the "Avatar" book was crafted in collaboration with series creators Michel Dante DiMartino and Bryan Konietzko to ensure the most authentic "Avatar" coloring experience.

The "Serenity" adult coloring book on the other hand is detailed with stunning black-and-white illustrations that follow your favorite moments from Joss Whedon's beloved "Firefly" TV series.

Take a look at the covers for both coloring books below:

Both books go on sale October 5, and are currently available for pre-order on Amazon.