Walls Within Walls is Maureen Sherry’s second novel, and it was first published in 2010 by Katherine Tegen Books. Sherry explores the hidden mysteries of New York City through the eyes of the Smithfork children—CJ, Brid, and Patrick—who team up with Eloise Post to uncover her father’s hidden legacy and, in the process, learn about the architect Raphael Guastavino. Sherry uses her middle grade writing style to appeal to a younger audience, within whom she hopes to inspire a new generation’s love of history, art, and literature.

All pagination references in this guide refer to the 2010 Katherine Tegen Books hardcover edition of the novel.

Plot Summary

The Smithfork children—Bridget (“Brid”), CJ, Patrick, and baby Carron—live a normal life in Brooklyn, New York, with their parents, Bruce and Anne, until their father’s tech company takes off. The family moves to a new apartment in Manhattan—an apartment the Post family once owned. When the three older children explore their new home, they soon discover a hidden mystery inside one of the walls—a library book that nobody returned. The children take the book to the library and, in return, receive a book of poetry from the librarian. The poetry book includes a key that opens a hidden dumbwaiter in the basement. Upon discovering the dumbwaiter, Patrick ascends to the upper apartments. While waiting for Patrick to return to them after his dumbwaiter ride, they meet Eloise Munn—whom the children recognize as Eloise Post from a picture their neighbors, the Williamsons, showed them of the Post family.

CJ and Brid work to convince Eloise to join their hunt and explore her father’s legacy, but she initially refuses. She believes they have overactive imaginations until they give her the poetry book from her father and a letter addressed to her informing her about the hidden legacy. The book initiates a renewed interest in the quest. Over several months, CJ, Brid, Patrick, and Eloise explore New York’s history through the eyes of Raphael Guastavino, a Spanish architect who created over 1,000 buildings in New York City. While they work to follow her father’s trail, they frequently encounter the mysterious Mr. Torrio—the Post family’s enemy due to the Posts blaming the Torrios for their son, Julian, going missing.

The further they venture into Mr. Post’s book, the closer the treasure hunters grow. In late winter, a snowstorm strikes Manhattan, and the Smithforks are traveling on the subway with Eloise when it breaks down. Patrick and CJ go to investigate while Eloise and Brid talk to Mr. Torrio, who reveals he is Eloise’s long-lost brother, Julian Post. The trio ventures into the tunnels with a team of firefighters to find CJ and Patrick; they do, and the children return to their home with new friends and a new appreciation for New York City’s history. Once they compile the clues, the Posts and the Smithforks go to the top of the building and uncover the hidden treasure in the water tower.