The play's action features a dinner party that is never seen onstage, but is reported by various characters. The foppish Sir Diaphanous Silkworm falls into a quarrel with the gruff soldier Captain Ironside, which causes Placentia to go into premature labour, thus revealing her illegitimate pregnancy. A complex tangle of misunderstandings is eventually unwound: fourteen years earlier, Polish switched her own infant daughter with the Lady's niece Placentia. The girl known as Placentia is actually Polish's daughter Pleasance, and the supposed Pleasance, serving as the false Placentia's maid, is the true heir. By the play's end, the two worthy and sensible men in the piece, Captain Ironside and Compass, prove themselves to be the suitable matches for aunt and niece.