At breakfast Duke Aubrey-Serrs chokes on his indignation, not his food. Eleanor reads the invitation, sees the name Ryce Penn, drops the paper, smiles, and calls it a joke. Her father does not laugh. He phones the police, shouts at reporters, and announces that a Serrs never lets an insult pass. Aunt Helena arrives, takes Eleanor's side, and decides to stay. Penn's first newspaper letters treat the duke's rage as entertainment: he apologizes for extraneous adjectives, calls the duke Father, and happily imagines becoming Penn-Aubrey-Serrs-Ellery. Every letter makes the duke look worse in print, and Eleanor hides the evening edition under her mattress and feigns deafness. The expensive invitations have already gone out to friends and acquaintances, so the whole joke is public before anyone can stop it. The hook is simple: Penn sounds like the mastermind, but the cost of the printing proves someone else with real money wanted this farce to happen.

At the witching hour, a glass panel is smashed. Penn and two accomplices bind Edward, the gardener, and Taylor, then use a series of knocks to confuse the duke while Penn slips upstairs. Eleanor wakes to a gunshot, hides in the borrowed bedroom, and hears the door open. Penn sits on her bed, introduces himself as her beloved fiance, and places a small gold ring on her finger. Haley was waiting outside, but a woman's scream makes him turn back to the house, and Penn escapes down a rope. The reversal is that nothing was stolen. The duke is outraged at being made a spectacle, but Haley insists Eleanor is not at fault. Eleanor gives him the ring, notices how well it fits and how warm it is from Penn's pocket, and realizes this thief did all of this just to put it on her hand. She cannot let the mystery stand, so she decides to go ask Penn herself.

Eleanor tracks Penn to his hideout by the smell of wheat flour on his clothes, asks him directly if he sent the invitations, and hears him say no. Penn locks her in a secure storage room for hours to protect his escape, and Haley rescues her the next morning with a note from the thief. Then the story turns violent. A criminal named Farnham, whom Penn humiliated by stealing back the proceeds of a deadly robbery, has Eleanor snatched off the street. He cuts her arms and her neck to force Penn to come out of hiding. Penn and Haley raid the warehouse together, with Penn lowering Eleanor out a window while Haley shoots through the door. Eleanor survives with scars. Haley is then called to Dominic Winfield's apartment, where the man who ordered the invitations has been bludgeoned with a malachite egg. The missing egg and the murder are now one case, and the wedding hoax has left a body behind.

A street boy named Raphael remembers seeing a man dump the malachite egg, and Penn finds the egg before the police do. Haley brings it into evidence. Eleanor, meanwhile, has been examining Edward's jacket and finds dried blood in the inside pocket. She takes the jacket to Haley, and Edward confesses. He persuaded Dominic Winfield to print the invitations because Edward's debts and Lady Helena's will gave him a desperate reason to see Eleanor married before her aunt died. When Dominic tried to go to the police after the kidnapping, Edward hit him once with the egg. The cousin who always seemed careless and kind was the killer all along. Edward is arrested, Eleanor apologizes to her former suitors, and Aunt Helena dies before the season ends. Haley asks permission to court Eleanor in plain words, she accepts, and at their wedding Penn appears disguised as Uncle Jae, tells Haley he stole his bride, and walks away because Eleanor asks her husband to let him go just this once.