Licquet had taken a fortnight to study the affair.  His only clues were Flierle’s ambiguous replies and the Buquets’ cautious confessions, but during the years that he had eagerly devoted to detective work as an amateur, he had laid up a good store of suspicions.  The failure of the gendarmes at Tournebut had convinced him that this old manor-house, so peaceful of aspect, hid terrible secrets, and that its occupants had arranged within it inaccessible retreats.  Then he changed his tactics.  Mme. de Combray and Bonnoeil had gone in perfect confidence to spend the afternoon at Gaillon; when they returned to Tournebut in the evening they were suddenly stopped by a detachment of gendarmes posted across the road.  They were obliged to give their names; the officer showed a warrant, and they all returned to the chateau, which was occupied by soldiers.  The Marquise protested indignantly against the invasion of her house, but was forced to be present at a search that was begun immediately and lasted all the evening.  Towards midnight she and her son were put into a carriage with two gendarmes and taken under escort to Rouen, where, at dawn, they were thrown into the Conciergerie of the Palais de Justice.

Licquet was only half satisfied with the result of the expedition; he had hoped to take d’Ache, whom he believed to be hidden at Tournebut; the police had arrested Mme. Levasseur and Jean-Baptiste Caqueray, lately married to Louise d’Ache; but of the conspirator himself there was no trace.  For three years this extraordinary man had eluded the police.  Was it to be believed that he had lived all this time, buried in some oubliette at Tournebut, and could one expect that Mme. de Combray would reveal the secret of his retreat?

As soon as she arrived at the Conciergerie, Licquet, without showing himself, had gone to “study” his prisoner.  Like an old, caged lioness, this woman of sixty-seven behaved with surprising energy; she showed no evidence of depression or shame; she did as she liked in the prison, complained of the food, grumbled all day, and raged at the gaolers.  There was no reason to hope that she would belie her character, nor to count on an emotion she did not feel to obtain any information from her.  The prefect had her brought in a carriage to his house on August 23d, and interrogated her for two days.  With the experience and astuteness of an old offender, the Marquise assumed complete frankness; but she only confessed to things she could not deny with success.  Licquet asked several questions; she did not reply until she had caused them to be repeated several times, under pretence that she did not understand them.  She struggled desperately, arguing, quibbling, fighting foot by foot.  If she admitted knowing d’Ache and having frequently offered him hospitality, she positively denied all knowledge of his actual residence.  In short, when Savoye-Rollin and Licquet sent her back to the Conciergerie, they felt that they had had the worst of it and gained nothing.  Bonnoeil, when his turn came told them nothing but what they already knew, and Placide d’Ache flew into a rage and denied everything.