Twins Axl and Ivan, with Sid as their driver, make a late-night fast-food run for a high school theater crew but return to discover that goo monsters are copying--and mutating--everything in sight.

"Charlie and August, the two cats that control the mechanical superhero dog, Sparks, are keeping the city safe. But when a second, evil Sparks shows up and starts causing trouble around town, everybody blames the real Sparks. Determined to prove that Sparks is still the hero everyone can count on, Charlie and August set out to uncover the shocking truth about who is responsible for all the chaos" -- Book jacket flap.