The Kill Clause by Lisa Unger

A hired killer finds herself caught between her conscience and her contract over the holidays in this riveting short thriller from the bestselling author Lisa Unger.

A hit woman’s work doesn’t stop for the holidays. As the advent calendar winds down, Paige slips into a palatial house, ignoring a blizzard of texts from her ex-husband. No surprise—Julian always gets maudlin this time of year. The real shock comes when the target is not alone. His young daughter is there too.
Risking the wrath of her organization, Paige retreats. There are some lines that, for personal reasons, she just won’t cross. But when she returns on Christmas Eve to finish the job, the girl is still there…along with someone even more startling. As the ghosts of her past gather—to haunt or to help, it’s unclear—Paige must confront old traumas and outwit her superiors to make it to Christmas morning alive.