Mr. Brooks proceeded to fill up the blank cheque for £500, imitating exactly the style of writing in the body of the genuine cheque. That was his part of the work. When that was done, and only the signature required, he handed both cheques over to Marston. That gentleman then subjected them to an ingenious process, into the details of which, from motives of prudence, it will be perhaps, as well not to enter. Neither spoke during the operation. When it was finished, Marston lifted the genuine cheque, and handed it to Brooks. ‘Look!’ he said. Brooks turned it over and glanced at the back. ‘Not a mark on it!’ he said, after examining it carefully. ‘Now look at the forgery.’ Mr. Brooks took the duplicate cheque and looked at it closely. ‘Why, there’s no signature at all!’ he said. ‘What’s the use of this?’ ‘That’s just the beauty of this process, my dear fellow,’ exclaimed Marston. ‘The old transfer business was clumsy, and almost sure to be found out. This, on the contrary, is elegant and defies detection. The man who invented this process made a fortune in America.’ ‘Why didn’t he come over here?’ ‘He met with an accident,’ said Marston, laughing. ‘He was shot in a drunken row. It was by the merest fluke that I got to know this process. I thought it might be useful some day.’ ‘But I don’t quite see the use of it,’ urged Mr. Brooks, still gazing anxiously at the apparently unsigned cheque. Marston took it from him, and drew from his pocket a little box containing a fine white powder. This powder he spread over the lower part of the cheque till it completely covered it. He left it so for a few minutes, then he took the cheque up and emptied the powder back into the box passing his fingers carefully down the paper to see that not a grain remained. ‘Now look at it,’ he exclaimed. Mr. Brooks did look, and he was delighted at what he saw. A faint violet signature was at the bottom of the cheque. It was perfect. Every dot, every line. ‘I guess the rest,’ he said. ‘Any special ink wanted?’ ‘None,’ answered Marston. ‘Fire away.’ Mr. Brooks did fire away. He went carefully over the faint violet outline with a pen and ink, and when he had finished and the signature was dry, he put the two cheques side by side, and dapped his thigh with delight. ‘By Jove, Marston, it’s perfect; the money’s in our pocket.’ ‘Not yet,’ answered Marston; ‘but it soon will be. What time will your clerk be back? We ought to send him to cash it at once. I shall cash the genuine one first, in case of accidents.’ Mr. Brooks’s face suddenly fell.