Despatching Zastrozzi to Naples to watch the movements of Julia La Marchesa di Strabozzi, and seize the first opportunity for murdering her, Matilda La Contessa di Laurentini migrates from her battlemented palace to her hotel in Passau, on the banks of the Danube, where she passes her time in meditating schemes for her rival’s extinction, and taking measures to get possession of her beloved Verezzi. On the failure of these measures, the Countess grows desperate, and in the violence of her despair is on the point of drowning herself in the Danube, when, instead of dropping in the water, she falls into the arms of a casual wayfarer. Of course, this casual wayfarer is Verezzi, who, after saving her from the guilt of self-murder, carries La Contessa off for the night to Claudine’s cottage. On the morrow, the Countess returns to Passau, attended by Verezzi, who henceforth lives with the lady till he expires in her presence.

Not that he yields at once to her overtures for his consent to their union. For a time, La Contessa Matilda gets nothing more agreeable from her domiciliation with her beloved Verezzi, than the pleasure of ministering to the brain-sickness and despondency of the invalid Count, who, regarding her by turns with frigid pity, distrustful tenderness, and vehement detestation, persists in vexing her ears with rapturous praises of his adorable Marchesa Julia. Acting on Zastrozzi’s advice, Matilda di Laurentini assures her guest that Julia is dead, and even causes him to think her dead. But vain the assurance, bootless its success! Instead of seeking consolation in the arms of La Contessa di Laurentini, the Count Verezzi persists in idolizing his Marchesa, protesting that he is bound to her for ever—as much bound to her now that she is dead, as he was bound to her when she was alive.

But though she cannot draw him to her embrace, Matilda La Contessa gains a gradually growing influence over the Count by ‘her siren illusions and well-timed blandishments.’ Soothing him in his wilder moods, cheering him in his dejection, Matilda di Laurentini diverts him with piquant speech, fascinates him with the music of her harp and voice, and animates him with the society she attracts to her salon. Playing the part of his ministering angel, she conceals from Verezzi the real nature of the passion, whose fierceness and animality would revolt him. ‘Her breast,’ the reader is told, ‘heaved violently, her dark eyes, in expressive glances, told the fierce passions of her soul; yet, sensible of the necessity of controlling her emotions, she leaned her head upon her hand, and when she answered Verezzi, a calmness, a melting expression overspread her features. She conjured him, in the most tender, the most soothing terms, to compose himself; and, though Julia was gone for ever, to remember that there was yet one in the world, one tender friend, who could render the burden of life less unsupportable.’

At length joy comes to this tender friend, whose demeanour is so mild and conciliatory to the Count Verezzi, though, in his absence, her bosom often heaves violently, whilst her dark and lustrous eyes emit glances, eloquent of the soul’s fiercest passion. Matilda La Contessa di Laurentini, and her idolized Count, have journeyed from Passau to yet another of her stately homes,—the Castella di Laurentini, standing in a gloomy and remote spot of the Venetian territory; a palace surrounded by a darksome forest, and lofty mountains that ‘lift their aspiring and craggy summits to the skies,’—when the lady achieves her purpose by a melodramatic stratagem.

To win the Count, she is admonished by Zastrozzi to ‘dare the dagger’s point,’ and is, at the same time, instructed by her counsellor how to dare it. In accordance with the instructions, Matilda La Contessa leads Verezzi to a convenient spot of her picturesque demesne—a spot where, on the right hand, the thick umbrage of forest trees would render indistinguishable any person lurking about; whilst on the left, there yawns a frightful precipice, at whose base a deafening cataract dashes with tumultuous violence around misshapen and enormous masses of rock, lying at the foot of the gigantic and blackened mountain, which rears its craggy summit to the skies.

Matilda and Verezzi are looking down the precipice, when a man, who has been instructed to play the part of an assassin, rushes with upraised dagger on the Count, who deems himself the mark of the bravo’s weapon. A second later, and the Contessa di Laurentini, hurling herself between the two men, receives the descending poniard in her right arm. Disappearing in the forest, the sham-bravo leaves the uninjured Verezzi with the wounded Contessa,—the one overflowing with gratitude to his preserver, whilst the other exults in the success of her artifice.

Soon after this theatrical scene, the Count, yielding to Matilda di Laurentini’s ‘siren illusions and well-timed blandishments,’ addresses her as his wife, adding ‘And though love like ours wants not the vain ties of human laws, yet, that our love may want not any sanction which could possibly be given to it, let immediate orders be given for the celebration of our union.’

Their marriage having received the vain sanction of human laws, Matilda and Verezzi enjoy a brief term of tempestuous bliss. On her wedding-day, ‘Matilda’s joy, her soul-felt triumph, is too great for utterance,—too great for concealment. The exultation of her inmost soul flashes in expressive glances from her scintillating eyes, expressive of joy intense—unutterable. Animated with excessive delight, she starts from the table, and seizing Verezzi’s hand, in a transport of inconceivable bliss, drags him in wild transport and varied movements to the sound of swelling and soul-stirring melody.’ By this time, the virtuous Verezzi has so completely succumbed to ‘siren illusions’ that instead of showing any disapproval of the Contessa’s forwardness, or any annoyance at being dragged about thus sportively, he exclaims with delight, ‘Come, my Matilda, come, I am weary of transport,—sick with excess of unutterable pleasure.’

In the earlier days of the honeymoon, one circumstance alone moderates Matilda’s happiness. Though the Count thinks Julia la Marchesa is dead, the Contessa has received no intelligence of a successful issue to her arrangements for her rival’s murder. This source of uneasiness passes away, however, for a time, when Zastrozzi assures the Countess he has removed Julia di Strabozzi with poison. But malignant fate soon puts a period to the feverish felicity of the husband and wife. Ere they have been married a month, Matilda La Contessa di Laurentini is summoned before the Inquisition. In their alarm at the letter of citation, the Count Verezzi and Matilda (albeit the latter has been warned by Zastrozzi to keep away from the capital) fly to a secluded dwelling in the eastern suburb of Venice, in the hope of living there in concealment from the agents of the dread Tribunal.

At Venice Matilda soon discovers that Zastrozzi’s warning was not given without reason. They have not been there many days, when one evening she and the Count behold the pensive and melancholy Marchesa di Strabozzi, gliding over the Laguna in her magnificent gondola, surrounded by ‘the innumerable flambeaux which blazing about rival the meridian sun.’ Whilst the Count discovers that the Marchesa, the real possessor of his heart, is still alive, the Contessa Matilda discovers that Zastrozzi has deceived her with a false announcement of her rival’s death. At the same time, the pensive and melancholy Julia di Strabozzi discovers that her Count Verezzi is living on terms of suspicious familiarity with Matilda di Laurentini.