There's a time of year that's full of cheer-but this December, not everything is quite so merry for Ava and Carol Detective Agency. For their holiday house-sitting gig has gone ho-ho-horribly wrong, and now Mr. Parker's prized painting is missing! With Christmas Eve approaching, the girls have little time to tie this burglary up in a bow, and so they'll need some help from their best friend Derik.

Using state-of-the-art hacking skills and the trained brains of the best super-sleuths in the business, Ava and Carol set out to unwrap this mystery. However, when the trail of clues leads them to a devastating personal discovery, all bets are off on whether this Christmas will be very merry after all. How can the girls reconcile terrible deeds when they are done by good people? And how can they turn their backs on a friend at a time like this?

Only with quick-thinking, fast fingers, and big hearts will Ava, Carol, and Derik retrieve the painting in time and put the real bad guys away for good.