Rachel Watts is still adjusting to the idea of Mycroft being her boyfriend when he suddenly departs for London with Professor Walsh. They are on the trail of a case involving the death of a rare books conservator in a carjacking, which seems to be connected to the theft of a Shakespeare First Folio from the Bodleian Library. Rachel is concerned about the similarities between this incident and the death of Mycroft's parents, prompting her to follow him to London.

However, Rachel's journey plunges her straight into a storm of trouble. As she joins Mycroft, they face the challenge of linking together three mysterious events: the theft of the First Folio, the conservator's death, and the tragic demise of Mycroft's parents. The question remains: Can Rachel help Mycroft make sense of these events, or is she at risk of losing him forever?

Every Word is a sophisticated thriller that blends a gripping mystery with a touch of romance, featuring the dynamic teen sleuthing duo of Watts and Mycroft.