La estación fantasma (Misterios en la gran ciudad, 2)

Cornelia and Miguel receive an old brick in the mail. Its sender doesn't want to reveal their identity but challenges them to solve a riddle in the New York subway. The kids discover that the mysterious brick belonged to Guastavino, the architect responsible for many of the city's wonders. But what connection does the subway riddle have to Guastavino? What secrets do the New York subway tunnels hold? Could it be related to the graffiti that has appeared in the neighborhood? Only Cornelia and Miguel will be able to find out.