As the subtitle indicates, "The Magnetic Lady" is a humours comedy, a form that Jonson had begun exploring three decades earlier and the last of the type that Jonson would write. The play is supplied with an Induction and a set of entr'actes that Jonson calls "Intermeans," through which the characters Probee and the ignorant Damplay have the play explained to them as it proceeds, by the Boy who's been left in charge of the "Poetique Shop." The focus of the play lies in the wealthy Lady Loadstone and her young, attractive, "marriageable" niece Placentia Steel. Placentia is the target of the amorous ambitions of a set of gulls and fools and hangers-on — Parson Palate, Doctor Rut, Bias, Practice the lawyer, and Sir Diaphanous Silkworm. Lady Loadstone's brother, Sir Moth Interest, is Placentia's financial trustee, and cares about little but maintaining control of her money. This crew is counterbalanced by two Jonsonian men of worth: Compass, Lady Loadstone's faithful steward, and his friend Captain Ironside.