As he was speaking, he dipped the slip of paper into the wine. The effect was instantaneous—the white was changed to a bright scarlet. Sainte-Croix uttered a feigned exclamation of surprise.

‘Poison!’ he cried, as he saw the change.

‘Ay—poison,’ repeated Lachaussée calmly. ‘Did I not well before I drank? It was doubtless intended for you, Monsieur Gaudin. Your cups are evidently not of Venice glass, or they would have shivered at its contact.’

‘This shall be looked into,’ said Gaudin, as he threw the remainder into the fireplace—‘and closely. But, at present, to business.’

‘Ay, to business,’ answered the other, as a most sinister smile passed across his ill-favoured countenance—the result of what had just occurred.

‘I have something to propose to you,’ said Gaudin, ‘if you feel inclined to join me in the venture. We have worked together before, and you know me.’

‘I do,’ answered Lachaussée, with meaning emphasis, as he glanced at the drinking-glass. ‘We can both be trusted to the same extent, for we are in each other’s hands.’

‘You allude to Milan,’ observed Sainte-Croix.

‘No,’ replied the other coldly; ‘to the château of M. d’Aubray at Offemont.’

‘A truce to this recrimination,’ said Gaudin. ‘Hear what I have to say. M. d’Aubray is dead—how, it matters not—and buried. One hundred and fifty thousand livres were to have been the legacy to his daughter, Madame de Brinvilliers, and, what was perhaps more, her absolute freedom to act as she pleased. The money has passed to her brothers, in trust for her, and she is entirely under their surveillance. This must be altered.’