Dog-lovers Kate and Lucie are back with more four-legged adventures! A new hot dog stand opens in town and the girls rush to try it out. The food is delicious, and the company is hard to beat—Molly and Wally have two hot-dog dogs of their own: Ketchup and Mustard. Almost as soon as the stand opens, though, Ketchup and Mustard have gone missing. It's up to Kate and Lucie to save the day, all the while dodging goofy boys and participating in the Bark-in-the-Park dog competition. These girls mean business!