The Empty Grave is the fifth, final, and most recent entry in British author Jonathan Stroud's "Lockwood and Co." series. Published in 2017, Stroud's novel is set four months after the events of The Creeping Shadow, the previous novel in Stroud's series. The Empty Grave follows Lockwood and his friends (including Lucy, George, Holly, and Quill) as they embark on a night mission to break into the Fittes Mausoleum, which is booby-trapped. They are breaking into the mausoleum to find and take the body of an acclaimed psychic named Marissa Fittes. But after they break into the mausoleum, they realize that their preconceived notions aren't as they appear. As well as that, their journey changes each person (and the agency that they operate) fairly significantly.
"Lockwood and Co." is one of the best-selling and most well-received series of all time. Each novel is beloved by critics and audiences alike; The Empty Grave is no exception. Goodreads called The Empty Grave is one of the best novels for students in middle and grade school. Common Sense Media likewise loved the novel, writing that it is a "Rousing finale to scary ghost series sure to satisfy fans."