Tabitha has enjoyed an entertaining afternoon in Julia's kitchen, but her return home is a bit jarring. As she arrives at her grandfather’s rue de l’Université mansion, a woman bursts out the door babbling about messages from spirits and a warning Grand-père must heed. Oncle Rafe angrily sends the woman on her way.

The very next night, Tabitha's messieurs host a soiree at their new restaurant, inviting fellow Resistance fighters from the war known as the Nine Bluets.

But shortly after the revelers leave the restaurant, one of Grand-père’s old friends is found dead on the street. When a second member of the Nine Bluets is found poisoned the next day, and a bluet flower is left with the body, Tabitha cannot ignore Madame Vierca's predictions about her dear messieurs. She has no choice but to share her suspicions and fears with the enigmatic Inspecteur Merveille.

Tabitha soon finds herself caught up in an investigation that takes her and Merveille to the seediest, most dangerous parts of the Left Bank. As she and Merveille desperately try to find a killer, they know they don’t have much time before the rest of the Nine Bluets are targeted . . . including Grand-père and Oncle Rafe.