With Anfitriaõ ou Júpiter e Alcmena (Amphitryon or Jupiter and Alcmene), staged at the Bairro Alto theatre in May 1736, a year after Os Encantos de Medeia, da Silva continued to explore an ancient corpus, as he would do until the end of his career. This specific work was inspired by Plautus’s Amphitruo, which had already inspired Molière in 1668, and a libretto written in 1690 by John Dryden for Henry Purcell.

Da Silva’s libretto was to music by Antόnio Teixeira. With this play, he attempted to create a form of serious comedy (the “joco-sério”), in which the marvellous assumes the form of a burlesque féérie: because the gracioso (comical valet) Saramago is hit several times and has unhappy love affairs with Iris and Cornucópia, he brings a burlesque contrast to the quartet made up of Júpiter, Juno, Anfitriaõ (Amphitryon) et Alcmena (Alcmene). The libretto was composed like music and the lines parallel each other almost symmetrically: every serious scene is mirrored by a farcical one – for instance, just as Alcmena faints before her two suitors, so does Cornucópia faint and transform into a dwarf when her two suitors are fighting. This burlesque is a pervading element of the play and even affects the music: for instance, a dog enters the stage in the middle of the scene and punctuates Saramago’s aria with his barks.

As in Vida do Grande D. Quixote and Esopaida, many metatheatrical allusions increase the comical dimension of the play: the old Cornucópia, Saramago’s wife, complains to Mercúrio (Mercury) about her husband scorning her, which he would not do were she “alguma destas bonecrinhas enfeitadas” (one of these small painted puppets); Saramago asks Mercúrio the following question, describing himself in passing: “E a vossa mercê não o convence também esta figura e este bonecro ?” (Are not this face and this puppet enough to convince your Highness?). Uncertainty about identity is a running theme of the play, as divine figures and statues are mixed up: Júpiter accuses Cupid’s “simulacro” of having made him fall in in love, and he breaks a statue of him; Júpiter himself will become, in the words of Tirésias, a new “simulacro” in the temple of Mars. Juno converses with an image of the nymph Iris, painted on a cloud. This uncertainty also affects humans: Mercúrio tells Saramago that “Alguma cousa és, porém és uma cousa postiça e fingida” (You are something, but a fake and ornamented thing).

The blurring of identities is thus a major theme, and the puppetry of the play leads to games with the audience. It infects the fable, as the figurative dimension of the bonecros is used to stage various transformations: Juno turns Saramago into an olive tree which bleeds when Júpiter engraves verses on the bark using a knifepoint; Corncucópia changes into a dwarf; later, her head turns and shows another face. This opera owes much to theatrical machinery and is thus also rich with other spectacular devices more typical of baroque theatre: Juno descends on a cloud; later, Júpiter also comes forward during the grand finale, in a prototypical deus ex machina.

Júpiter, madly in love with Alcmena (Alcmene), sets up a stratagem imagined by Mercúrio (Mercury): while the beautiful woman laments the absence of her husband, the general Anfitriaõ (Amphitryon), who has gone to war, the god disguises himself as her husband and goes to see her. As for the servant Cornucópia, she is talking with Mercúrio, disguised as her husband Saramago. When Saramago arrives and announces his master’s return, he sees Mercúrio, disguised as him: disconcerted, he cannot guide his master when he asks him how the news was received in the house. Juno, Júpiter’s wife, decides to avenge herself for his infidelities. Calling herself Felisarda, she comes down to Alcmena’s house; Júpiter has just left. When the real Anfitriaõ returns, even Juno is fooled and believes that he is in fact her husband Júpiter. The scene also leads to a series of misunderstandings between Anfitriaõ and his wife, who believes that she saw him the day before, and between Saramago and Cornucópia, who reproaches him for his rudeness. Determined to keep the ruse going, Júpiter goes as far as deceiving the soldiers and usurps Anfitriaõ’s military victory.

The nymph Iris, disguised as Corriola, attempts to find out the truth by seducing Saramago. Tirésias, in love with Juno, who is pretending to be the daughter of Anfitriaõ’s enemy, agrees to help her: they will take revenge against their husbands. The couples quarrel and reconcile: jealous when she hears the romantic conversations between Saramago and Iris, Cornucópia is forced to think about her own unfaithfulness with the other Saramago. In the meantime, Júpiter reconciles with Alcmena, who was angry with him after a quarrel about the real Anfitriaõ. Mercúrio stops Anfitriaõ from coming by refusing to recognise him: this leads to a violent struggle between the master and his “valet”; when the real Saramago arrives, he is beaten. Anfitriaõ and Saramago break through the door and force Júpiter to leave the house: Anfitriaõ comes face to face with his lookalike. The two suitors are about to kill each other, but they are interrupted by Alcmena, who faints. The scene is paralleled by a confrontation between Mercúrio and Saramago, in front of Cornucópia, who also faints and turns into a dwarf. When Saramago discovers Tirésias and Juno’s love affair, the goddess turns him into an olive tree: Mercúrio and Cornucópia knock down its fruits, then Júpiter engraves the name of his beloved on it, before giving Saramago his original body back. Júpiter meets Alcmena, who is sleeping by the fountain. He is challenged by Anfitriaõ. Mercúrio testifies on behalf of his master, against the real Anfitriaõ. The couple is in a predicament: Tirésias sentences Alcmena to death for her infidelity; doing so, he obeys Juno; Anfitriaõ is put in prison, where he beats Saramago for being the cause of his misfortune. However, the gods intervene, so that the play has a happy ending. Juno frees the prisoners; then, when Alcmena is about to be sacrificed, Júpiter reveals the truth: the stage transforms into an empyrean.