Mandie couldn't have been more excited when her mother said she could travel to New York City with Celia and Jane Hamilton to visit Jonathan Guyer and his father for the Thanksgiving holidays. Arriving by train with a firm grip on Snowball, Mandie is overwhelmed by the city's monstrous buildings and people racing everywhere. When Mr. Guyer insists that they stay at the Guyer mansion, it's even better because now they'll be close to Jonathan. But there are strange things going on at Jonathan's house. Who is the strange girl who demands that Jonathan give her the stray dog they found in the Guyer backyard? And who is the foreign-speaking man whom Mandie discovers meeting in secret with the butler? What's really going on behind all the closed doors of the mansion? The strange man leads them far from home. Is it a trap?