Set against the background of 1930s England, Jewel of the Thames introduces Portia Adams, a budding detective with an interesting -- and somewhat mysterious -- heritage. Nineteen-year-old Portia Adams has always been inquisitive. But when her mother dies, Portia can't figure out why she was left in the care of the extravagant Mrs. Jones. She doesn't have long to dwell on it before she is promptly whisked from Toronto to London by her new guardian. Once there Portia discovers that she has inherited 221 Baker Street -- the former offices of Sherlock Holmes and Dr. Watson. Portia settles into her new home and finds herself entangled in three cases, the first involving stolen jewelry, the second a sick judge and the final case revolving around a missing child. But the greatest mystery of all is her own. How did she come to inherit this townhouse? And why did her mother keep her heritage from her? Portia has a feeling Mrs. Jones knows more than she's letting on. In fact, she thinks her new guardian may be the biggest clue of all.