Gary carries out the final days of his prison sentence aboard the Galaxy One, when he meets Mooncake, an alien who is being chased by bounty hunters; Gary swears to keep Mooncake safe, not knowing the alien is a planet-destroying super weapon.
Gary and Avocato must chase down the ruthless bounty hunter, Terk, before he can tell the Lord Commander that Mooncake is aboard the Galaxy One.
Gary tries to hide Mooncake safely away on the planet Yarno. But instead, Gary and Avocato are trapped in a terrifying mind-puzzle, while Mooncake is taken from them, and forced to fight in a combat arena called the Deathcropolis.
After the Galaxy One is hacked by the Infinity Guard, Gary has to harvest energy from a nearby star to reignite the engines; the radiation poisoning from the star sends Gary into a trance of painful memories; Gary and Quinn are finally reunited.
Gary goes on a mission to save Avocato's son, Little Cato, from Lord Commander's Prison Planet, but it turns out to be a trap; Quinn sees Gary's vlogs and understands that he is someone who would risk his life for any of his friends.
Gary grapples with his future when he learns his prison sentence is up. Meanwhile, everything gets turned upside down when Quinn and Quinn's Future Self (Nightfall) vie for the love of Gary as they try to save the universe.
Gary and the Crew encounter a Titan in Inner Space, who informs them how to close the breach in the fabric of space. Gary gets a chance to spend time with his father for the first time as an adult, moments before his father's ship explodes.
Gary and Quinn go back to Earth to find an anti-gravitational bomb that can close the breach in space. Gary and Quinn decide to turn this life-threatening adventure into their first date.