After her near-fatal run-in with the Jack the Ripper copycat, Rory Deveaux has been living in Bristol under the close watch of her parents. So when her therapist suddenly suggests she return to Wexford, Rory jumps at the chance to get back to her friends. But Rory’s brush with the Ripper touched her more than she thought possible: She’s become a human terminus, with the power to eliminate ghosts on contact. She soon finds out that the Shades - the city’s secret ghost-fighting police - are responsible for her return. The Ripper may be gone, but now there is a string of new inexplicable deaths threatening London.

At the end of Maureen Johnson's New York Times bestselling novel, The Madness Underneath, Rory, Callum and Boo are reeling from the sudden and tragic death of their friend and squad leader, Stephen. The Shadow Cabinet picks up where listeners left off, and now Rory is convinced there must be a way to bring Stephen back. Meanwhile, new dangers arise: Rory's classmate Charlotte is missing, and Jane and her nefarious organization are clearly planning something big.

Ellingham Academy is a famous private school in Vermont for the brightest thinkers, inventors, and artists. It was founded by Albert Ellingham, an early 20th century tycoon, who wanted to make a wonderful place full of riddles, twisting pathways, and gardens. "A place", he said, "where learning is a game." Shortly after the school opened, his wife and daughter were kidnapped. The only real clue was a mocking riddle listing methods of murder, signed with the frightening pseudonym "Truly, Devious".

Ellingham Academy must be cursed. Three people are now dead. One, a victim of either a prank gone wrong or a murder. Another, dead by misadventure. And now, an accident in Burlington has claimed another life. All three in the wrong place at the wrong time. All at the exact moment of Stevie's greatest triumph.... She knows who Truly Devious is. She's solved it. The greatest case of the century.

The Truly Devious case - an unsolved kidnapping and triple murder that rocked Ellingham Academy in 1936 - has consumed Stevie for years. It’s the very reason she came to the academy. But then her classmate was murdered, and her parents quickly pull her out of school. For her safety, they say. She must move past this obsession with crime. Stevie’s willing to do anything to get back to Ellingham, be back with her friends, and solve the Truly Devious case. Even if it means making a deal with the despicable Senator Edward King.