Can Lord Peter Wimsey prove that Harriet Vane is not guilty of murder - or find the real poisoner in time to save her from the gallows? Impossible, it seems. The Crown's case is watertight. The police are adamant that the right person is on trial. The judge's summing-up is also clear. Harriet Vane is guilty of the killing her lover. And Harriet Vane shall hang. But the jury disagrees.