Nothing goes better with the circus than a good wiener! So, when Neon Wiener is offered a position as the official food cart for Crostini's Cosmic Carnival and Wonder Circus Train, Humphree is over the moon. Cosmoe feels more skeptical that the offer may be too good to be true, but after he unexpectedly demonstrates incredible monster-taming skills in a heroic display, he's hooked.

The circus-goers can't get enough Galactic Hot Dogs, and between the death-defying acts and highly unusual employees, the carnival offers endless entertainment for Cosmoe, Humphree, and Princess Dagger. But they soon discover there's more to the glitz and showmanship than meets the eye--in fact, the hot-dog-loving crew may be in more danger than ever before. And getting to the bottom of the circus's secrets may mean confronting Cosmoe's troubled past.