In the 1800s, firefighters used horses to pull fire trucks. But horses spook easily and run away from fire-so they needed fire dogs. And there's no better fire dog than Sparky. Sparky is so good at her job, she knows when the alarm is going to ring before it even rings! But today is no ordinary day. There's no choice but to put Cinders-a rescue horse with an attitude-to work at her very first fire, one destined to become one of the greatest disasters...