In The Prestige, the secret to Angier's 'Real Transported Man' trick is that he is effectively cloned while teleporting, and the original Angier is drowned when disappearing under the stage.
When Alfred Borden went behind the stage to investigate the trick and find out Angier's secret (and discovering Angier dying in the water tank), he was accused of murdering Angier.
But what happened to the transported 'clone' of Angier? If he presented himself as was normal for the trick, no one would've thought Angier died. So how did the 'clone' know to not appear?