On 31 December, the movements of the barges between Bouin and Barbâtre alerted the besieged who expected an imminent attack. Throughout the end of December, the Vendeans fortified the various artillery batteries scattered around the island. Hyacinthe Hervouët de La Robrie and Dubois de La Guignardière developed a system of lights to warn the town of Noirmoutier in case of an attack. The stones and the beacons of the Gois causeway were destroyed. A messenger was also sent to Charette to ask for help.Desmortiers and Lucas de La Championnière give no information on this. For René Bittard des Portes and Julien Rousseau, a message from d'Elbée is carried by a Bretonne named Marie Lourdais. According to the former, she joined Charette in Touvois and for the latter, in Vieillevigne. For Françoise Kermina, Marie Lourdais was the messenger who informed Charette of the fall of the island. While according to Desmortiers, this news is brought by an officer of the marshes of Soullans who delivers a certainly apocryphal account according to Lionel Dumarcet. According to Dumarcet, the only evocation of a messenger concerns the Cavalier de Massip.
