It concerns a 12-year-old boy named Kenny Huldorf who has moved to a new area and discovers a ghost, Caleb, in a room.

Kenny travels back in time with Caleb to find his murderer and comes to a dilemma on whether he can return to the present or save his new friend.

Something Upstairs is about a twelve-year-old boy, Kenny Huldorf, who tells a story to Avi who had visited the school on a book tour.

Secrets.” Kenny visits the local library, where he meets an old historian, Pardon Willinghast, who is also curious about the property.

Kenny tries to talk with the ghost boy, who mutters the word “slave.” He asks Willinghast if any former owners had slaves, but he doesn't get a candid answer.

After getting a sample of the floor analyzed by a chemist, Kenny talks with the slave boy, whose name is Caleb, who affirms that's his blood, and that he was murdered in his sleep.

Another man sees Kenny and asks him to pass a message, which he does, but he also reads it, noting it concerns a meeting aboard The Gaspee.

Kenny confirms in the news articles that Caleb was found dead in the locked attic room in an apparent suicide.

Then the angry drunken mob approaches, but Caleb confronts them, and gets hit in the face with a rock before Kenny pulls him back.

In order to return to the present time, Kenny will have to kill Caleb in the room, and then lock it from the inside to fulfill the suicide scenario.

When asked if the story is real, Avi responded that “it’s true if you believe in time travel and ghosts.

A list of notable formats is as follows: The Rhode Island Historical Society hosts the Avi Tour, which walks through some of the places and the waterfront districts in Providence mentioned in the book.