The Count, now doubly jealous, imagining that Cherubino had also been making love to Susanna, began to pour forth abuse on them both, and declared that Figaro should be told of his bride-elect's duplicity; but Susanna, assured of Figaro's trust in her, pleaded only for Cherubino's pardon, slyly reminding her master that the page had overheard his words of love to her, and should on that account be conciliated. Almaviva, thus compelled to admit the prudence of such a course, then agreed to pardon Cherubino, but only on condition that he set off immediately for military service, to command a company in the Count's own regiment; and the page was ordered to start for Seville at once.
Meanwhile, the Countess Almaviva had also been told of her husband's infatuation for the waiting-maid; and knowing that Susanna was too faithful to betray her, she bade the girl fetch Figaro to her boudoir, that the three might concoct a plot by means of which her husband should be exposed, and, thus cured of engaging in such intrigues, be led back to the arms of his still loving wife.
Figaro's keen wit soon furnished a scheme, and he said that he would send an anonymous letter to the Count, informing him that the Countess intended to grant a secret interview to a certain gallant at the revels to be held that night, which would rouse his jealousy to such a pitch that, whilst endeavouring to prove his suspicions, the wedding could take place before he had time to prevent it. He also suggested that, to entangle him further, Susanna should grant the Count the twilight meeting in the garden he had asked for, but that Cherubino, who had not yet departed, should take her place, dressed in her garments; and then the Countess should surprise the pair, and compel the Count, after thus discovering him in an intrigue, to sue for pardon and return to her affections.
The Countess gladly agreed to this plan, and Figaro, having despatched the letter to the Count by the hands of Basilio, sent the page to the boudoir to be dressed for his part. Cherubino, delighted to be once more in the company of his beloved mistress, readily entered into the plot, and Susanna, after locking the door to prevent interruption, began to dress him in a gown and head-dress of her own, the page's fresh complexion and curling hair helping to make the disguise more complete.
But just as Susanna had gone into an inner room to look for a ribbon, the Count himself knocked at the boudoir door, and finding it locked became suspicious and demanded to have it opened. Full of terror Cherubino ran to hide in a dress cupboard, which the Countess hastily locked, placing the key in her pocket; and then she admitted the Count, who was rendered more suspicious than ever on observing her confused looks.
Remembering the anonymous letter he had just received, he declared that she had a lover hidden within the cupboard, having heard a sound of shuffling from its depths; and when the Countess tremblingly announced that it was only Susanna, who had retired there, interrupted in the act of trying on a new dress, he angrily called on the maid to answer to her name. Cherubino, however, kept silence, and Susanna, who had returned unobserved and was now hidden behind a curtain, dared not speak. The Count now felt that his suspicions were confirmed, and, in a storm of jealousy, he dragged off the Countess to get tools to break open the cupboard, first locking the doors of the boudoir and inner chamber so that the captive should not escape.
As soon as they had gone, Susanna rushed to the cupboard and unfastened the door with a duplicate key she carried in her pocket, and Cherubino rushed wildly out, freed of his borrowed garments, which he had hastily discarded. Finding all the exits locked, he opened the window and sprang lightly into the garden below; and Susanna, having assured herself that he had come to no harm, took his place in the cupboard, fastening the door on the inside just as the Count and Countess returned.
The Count had brought tools to break open the cupboard lock, but the Countess, seeing that he was in earnest, produced the key, and in despair opened the door herself. A sigh of relief and wonder escaped her as Susanna stepped forth; and the Count, dumbfounded and ashamed of his suspicion, instantly sought pardon of his wife. However, remembering the letter he had received, he asked what it meant, and the Countess told him that it had been written by Figaro at her orders to provoke jealousy. But on Figaro himself entering at that moment to announce that the wedding guests were assembling, the Count decided to test the truth of this statement, and showing him the letter, he asked if he knew anything about it. The valet, not knowing that his master had been told the truth, at first denied all knowledge of it, and it was not until after sundry meaning glances from the Countess, and saucy pinches from Susanna, that he guessed his mistake, and admitted writing the note.
The situation might now have been saved had not old Antonio, the gardener, just then entered with several broken flower-pots in his hands, which he tearfully declared had been smashed by a man whom he had seen jump from the window of the boudoir into the very midst of them only a few minutes ago; and the Count's suspicions were quickly roused again.
But Figaro, warned by the distracted looks of the Countess and Susanna, immediately announced that it was he who had made the leap, explaining that he had been waiting for Susanna, when, on hearing his master's angry voice, he had become alarmed, remembering the letter he had written, and had jumped from the window to escape his presence.