During a women's fashion show for undergarments, a brick is thrown through a window by a protester. When a model is found dead, it is assumed she was hit in the head by the brick - but Dr. Grace and Detective Murdoch determine the model was killed by an ingenious mechanism in the corset being modeled. Who did it - the designer and fashion show presenter? - the corset manufacturer? - the protester who threw the brick? - one of the other models? Or was it someone else?