What if the house was the only witness? 

Every camera, smart lock, voice assistant, and sensor in the house recorded something that night. The problem is that none of it makes sense. Security footage is missing. Door logs don't match witness statements. And the home's AI seems determined to answer Charles's questions without ever revealing the truth.

As he digs into the lives of Mercer's family, business partners, and employees, Charles discovers that everyone has something to hide—and someone is willing to use the very technology designed to protect the house to conceal a murder.

To catch the killer, Charles will have to determine whether the smartest witness in the room is helping him solve the crime… or helping someone get away with it.