Donald and Penumbra must break out of a Moon Prison and send a warning to Earth about a looming invasion; Dewey and Webby uncover a sinister conspiracy targeting their family.
- David Tennant as Scrooge McDuck
- Danny Pudi as Huey Duck
- Ben Schwartz as Dewey Duck
- Kate Micucci as Webby Vanderquack
- Tony Anselmo as Donald Duck
- Julie Bowen as Penumbra
- Lance Reddick as General Lunaris
- James Adomian as Jones
- Rob Paulsen as Gibbous
- Laura Bailey as Palus, Mail Lady
- April Winchell as Zenith
- Kari Wahlgren as Roxanne Featherly
- Dewey mentions a possible fourth sibling that he names Phooey based on their childhood photos of them as eggs, only to be corrected by Scrooge that the fourth "egg" is really a mustard stain. In the Donald Duck comics, sometimes a fourth nephew is depicted through artistic error, who came to be named Phooey by fans. A story playing off of this would explain Phooey as a child who would blink in and out of existence at random.
- Donald's return to Earth in the space capsule is an homage to Stanley Kubrick's 2001: A Space Odyssey, featuring the tune of Blue Danube and Donald staring into the "Star Gate".
Community content is available under CC-BY-SA unless otherwise noted.