'Tis the season...for murder.

Christmas has arrived in London, and for the first time in two years, Rosemary Lillywhite has much to celebrate.

Her relationship with Max is moving in the right direction; her brother and best friend are hopelessly in love and as happy as they've ever been; and the family's booming textile business is expanding into America.

Riding high on holiday cheer, Rosemary isn't even daunted by the arrival of her overbearing mother, Evelyn, who has come to London to attend the company's annual children's charity event.

She should have known it was all too good to be true.

Before the festivities can even begin, one of Rosemary's father's employees turns up dead, and another case must be solved before Christmas is ruined!

Except this time, Evelyn isn't content to sit on the sidelines of the investigation, not with the family's reputation on the line.

When it turns out Evelyn is no slouch in the deduction department, Rosemary might have to do the unthinkable - admit she could still learn a thing or two from her mother!