Tartuffe is a five-act verse comedy set in a single Paris household. Orgon, a prosperous and otherwise sensible man, has taken in a poor stranger named Tartuffe who presents himself as a model of piety. Orgon and his mother, Madame Pernelle, are completely taken with him, while everyone else in the family sees a fraud and says so plainly.
The first acts establish the split. Dorine, the sharp-tongued maid, mocks Orgon's infatuation; he answers her every report about his sick wife with a doting 'Poor man!' for Tartuffe instead. Orgon decides to break off his daughter Mariane's match with the man she loves and hand her to Tartuffe, and he brushes aside his brother-in-law Cléante's careful argument that true devotion looks nothing like this showy kind.
Tartuffe finally appears in the third act, performing humility, and then drops the act in private by making a frank pass at Elmire, Orgon's wife. Orgon's son Damis overhears and denounces him, but Tartuffe responds with such theatrical self-accusation that Orgon believes the slandered saint over his own son, disinherits Damis, and deeds his entire property to Tartuffe on the spot.
Elmire then proposes to show Orgon the truth directly. She has her husband hide under a table while she draws Tartuffe out, and he obliges, pressing his suit and explaining that heaven's commands can be quietly arranged around. Orgon, hearing it himself, finally erupts and orders Tartuffe out, only to learn that the deed of gift and some compromising papers now put the family at the impostor's mercy.
Tartuffe turns on his benefactor, brings an officer to evict the household, and reveals he has denounced Orgon to the king. The reversal comes from outside the family: the officer arrests Tartuffe instead, on the king's order, the monarch having seen through the swindler, recognized him as a known criminal, voided the gift, and pardoned Orgon. The play ends with the impostor jailed and the interrupted marriage restored.