Theodosia Throckmorton is in a fix. Allowed to attend a reception given by one of the directors of her parents’ museum, she stumbles across Mr. Tetley of the British Museum—in most unusual circumstances! Since Theo has last seen him in a showdown in an ancient Egyptian tomb, his reappearance could mean only one thing: the Serpents of Chaos are back. Once again Theodosia will have to take on secret societies, evil curses, and dark magic too sinister to imagine, especially if it falls into the wrong hands. Blocked at every turn, Theodosia will have to rely on her own skill and cunning—along with a little help from the most unexpected places.

Being able to detect black magic isn't all tea and crumpets—and for Theodosia Throckmorton, it can be a decidedly tricky business! When Sticky Will drags Theo to a magic show featuring the Great Awi Bubu, she quickly senses there is more to the magician than he lets on, setting in motion a chain of events she never could have bargained for. Meanwhile, back at the Museum of Legends and Antiquities, Henry is home for the spring holidays and makes an accidental discovery of an artifact that alchemists have been hunting for centuries. Soon, every black-cloaked occultist in London is trying to get their hands on it . . .

In this fourth book in the series, Theodosia sets off to Egypt to return the Emerald Tablet, along with its knowledge of some of the ancient world's most guarded secrets. Accompanied by her cat, Isis, (smuggled along in a picnic hamper), Theo plans to return the artifact, then explore the mysteries surrounding her own birth. But nothing ever works out as planned, especially when the Serpents of Chaos are involved . . . But nothing ever works out as planned, especially when a precious treasure appears suddenly, and then just as suddenly disappears . . . When the Serpents of Chaos get involved, Theo finds she's digging up a lot more than she expected!