Upper Edmonton Gardens looks forward to a jolly Christmas, until one humbug sings of murder-in Mrs. Jeffries's 26th mystery.

'Tis the week before Christmas, and all through the house, every creature is stirring...

But just as Inspector Witherspoon's staff prepares for the long-awaited wedding of Betsy and Smythe, a Yuletide murder falls in the Inspector's lap.

A middle-aged spinster has been killed in what her murderer hoped would look like a random crime. But the Inspector's investigation reveals a web of lies, intrigue, and long-buried secrets. With uncooperative witnesses, sulking relatives, and a second Christmas wedding, a simple investigation seems unlikely. And the household will have to put aside its holiday spirit to save the Inspector's reputation.