The "_agent provocateur_" the person who incites a fellow-citizen to commit a crime in order that the police may make a clever capture or secure a dangerous criminal who has hitherto evaded their well-spread net, is not, fortunately, a conventional character in the British judicial drama. But there are men and women who put up burglaries and robberies and criminal schemes in order that they may give information and get their victims caught in the act. Not long ago a young policeman captured a man with a quantity of silver plate in his possession. The man was coming from a house in the suburbs at an early hour in the morning. When the man was brought before the magistrate he told in self-defence a most extraordinary story. He was an ex-convict, but he was leading an honest life and working under the police. He called a police officer as a witness on his behalf, and the officer acknowledged that the man's story was correct. The prisoner had given information that a burglary was to be committed, and had, "in the interests of justice," taken part in it himself. When he was captured he was on his way to take the stolen property to the police-station, and the information he had given had enabled the authorities to secure the other men. "The prisoner was discharged." If you read between the lines of this story you will have a fair idea of the way in which the professional "nark" works in connection with what--at least, so far as he is concerned--is a put-up job--a trap deliberately arranged for the capture of a criminal. When a sensational crime has been committed by confederates or by a "gang," and the hue and cry continues unabated, it sometimes happens that one of them tries to make himself safe by offering information to the authorities on certain well-under-stood conditions. "King's evidence" is recognized as a necessary evil, for it is occasionally the only evidence upon which a conviction could possibly be obtained. Turning King's evidence does not always save the traitor. He may escape the punishment of the law, only to meet with a tragic fate at other hands. Carey, one of the informers at the Phoenix Park murder trial, was got safely away, only to be shot dead by Patrick O'Donell on board a steamship near Port Elizabeth, South Africa. Other informers less notorious met with "fatal accidents" in far-off lands. Two who went to Paris and lived under assumed names came to the Morgue. They were "found drowned" in the Seine. The informer in the great bank-note forgery case was doomed to death by the men whom he had betrayed. The revolver with which the elder Barmash committed suicide after sentence had been passed upon him was intended to be used upon the informer who stood in the dock a fellow-prisoner. The opportunity of shooting him did not occur. The man was never in a position in which he could be safely aimed at.