|The Swarm at the Edge of Space|
|Original broadcast||December 12, 2008|
|Series||The Secret Saturdays|
|Overall episode number||10|
|Written by||Brooks Wachtel|
|Directed by||Scott Jeralds|
|Previous episode||The Owlman Feeds at Midnight|
When the Saturdays rescue an aircraft under attack by a swarm of Atmospheric Jellyfish, they discover that it's Agent Epsilon and his son Francis, who does nothing but play a video game the entire time. The Jellyfish turn on their airship, covering the solar panels to prevent any escape. Epsilon is injured by one of the Jellyfish in the ensuing battle. Doc attempts to electrify the hull to scare the Jellyfish off, but it fails to deter them. Zak and Francis head for the ship's antenna to call for help, and Zak discovers that Francis is actually responsible for provoking the Jellyfish, as his "game" is actually a prototype control device that's driving them crazy. The creatures steal the device, further infuriating them, so Francis forces Zak to use his powers to capture one of the Jellyfish for study. Zak obliges, but grabs the one which stole the control device, causing them to pursue Epsilon and Francis once they depart.
- Upper Atmosphere, Earth
- Francis's glove in the area of his thumbs disappears and then reappears when he plays his "game" after his dad got stung.