The Whispering Skull, which was published in 2014 by publisher Disney-Hyperion, is the second novel in author Jonathan Stroud's acclaimed young adult series "Lockwood and Co." In The Whispering Skull, the number of spirits and hauntings have decreased to minute levels in London. Bored, Lockwood and Company creates a bet with their rival agency, called the Fittes agency. When one of the two agencies eventually loses, they have to publish something in the local newspaper admitting they had been defeated. Shortly after the agency makes the bet, though, a man comes into Lockwood and Co.'s office and asks them to seal the coffin of a man named Edmund Bickerstaff. Things go well for the agency initially. However, one of the members of the agency makes a mistake and unleashes an awful spirit and something called a Source, which kills whoever looks at it. Because of this mistake, they must work hard to stop the spirit and the Source before it kills people.
The novels in the "Lockwood and Co." have been adapted into a television series on streaming giant Netflix. That series, which was released in late January 2023, much like the novels on which it is based, received very positive reviews from critics and audiences alike. The Whispering Skull received incredibly positive reviews when it was published. Kirkus Reviews loved the book and said that the book contains "Rousing adventures for young tomb robbers and delves into realms better left to the dead." The Guardian felt similarly. In their review of the novel, they wrote, "The amount of suspense [in the novel] was terrific and I can't wait for book three in the series. I would recommend it to children 10+ who enjoy ghostly scares, thrills, and throw-your-head-back laughter. A great suspenseful read, go check it out!"