This article contains spoilers for the two-part Episode 11 of The Sandman Season 1, "A Dream of A Thousand Cats / Calliope."

Netflix delighted fans of its new hit series The Sandman today with a surprise bonus episode to cap off Season 1, consisting of one animated and one live-action story based on classic issues of the source comic series by Neil Gaiman.

The new episode appeared on Netflix today, Aug. 19, with no prior announcement to promote it. The first half, "A Dream of A Thousand Cats," offers an artistic adaptation of the comic issue of the same name and stars a number of new feline characters, in addition to introducing the cat form that Dream of the Endless takes to communicate with them. The Sandman lead actor Tom Sturridge returns for the episode to voice his character in the special, joined by a cast of guest voices.

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Two Mini Masterpieces of The Sandman

The second part of the episode adapts the issue titled "Calliope." This dark chapter of The Sandman universe tells the story of the titular Greek Muse, who has been imprisoned by a writer named Richard Madoc to take advantage of her divine inspiration. In the episode, Calliope is played by Assassin's Creed's Melissanthi Mahut, while Arthur Darvill, known for his roles on Doctor Who and DC's Legends of Tomorrow, plays Madoc.

Additional voice actors in "A Thousand Cats" include Sandra Oh, Rosie Day, David Gyasi, Joe Lycett, James McAvoy, Nonso Anozie, Tom Wu and Diane Morgan. Gaiman himself will guest star as the Skull Bird, and the two stars of his series Good Omens, David Tennant and Michael Sheen, play roles opposite their real-life partners Georgia Tennant and Anna Lundberg, respectively. Hisko Hulsing is both director and production designer, and describes the animation saying, "We endeavored to make the animated version of 'A Dream of a Thousand Cats' as mesmerizing and hypnotic as we could by utilizing the magic of real oil paintings on canvas. We combined the paintings with classically drawn 2D animation, based on realistic 3D animation of telepathic cats in order to create a trippy world that feels both grounded and dreamy at the same time. Untold Studio’s in London created the breathtaking 3D animation of the cats. The wonderful 2D animation, oil paintings and stylizing were all done at Submarine Studio’s in Amsterdam."

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The guest cast for "Calliope" in addition to Mahut and Darvill includes Nina Wadia, Souad Faress, Dinita Gohil, Kevin Harvey, Amita Suman and Derek Jacobi. The director for the episode is Louise Hooper, with Gary Steele as production designer.

All eleven episodes of The Sandman's first season can be streamed now on Netflix. The series has enjoyed immense success since its Aug. 5 release, but has not yet been officially greenlit for a second season.

Source: Netflix