I Left My Sneakers in Dimension X is the second book in the children's science fiction series Rod Allbright's Alien Adventures.

Rod and Elspeth are rescued by Captain Grakker and his crew, but during the escape from Castle Chaos, the Ferkel is damaged enough that all must abandon ship.

Following the strange disappearance of their friend Snout, the seven remaining gain help in the form of Galuspa, one of the race of Shapeshifters that are native to Dimension X.

They find out that he is actually the egg brother of their missing comrade Snout, and that Smorkus Flinders was once a good person, but, when he was slightly older than Rod, he was caught in a horrific Reality Quake that permanently transformed him into a monster.

Returning to Castle Chaos (in part with help from Spar Kellis, a gigantic blue monster who works for the Ting Wongovia by spying on Smorkus Flinders), they make their stand.

During the battle, he is contacted by Snout (by way of a direct telepathic link between the two), and learns that his old friend is being held captive by the "Ferkada".