“Yes, that theory hangs together; but I’m not satisfied with it. There seems to me to be every reason to believe that the murders were most carefully thought out beforehand, and in that case the sending of the telephone message needs a lot of explanation. Then, again, we have still no indication at all of how Walter Brooklyn, or for that matter George Brooklyn, got into or out of the house.” “On that point I have absolutely failed to get any light. My first idea, of course, was duplicate keys, and the stable yard. But the yard was quite definitely bolted as well as locked by eleven o’clock. The wall could not be scaled without a long ladder, which is out of the question. The front door is quite impossible, unless three or four servants were in the plot. I suppose they must have slipped in through the theatre, although it beats me how they got in without being seen.” “May not Walter Brooklyn have come in through the stable yard before it was closed, and been in the house some time before the murders? He may have been going away when your taxi-man saw him at about 11.30.” “Even so, that doesn’t explain how he let himself out and bolted the place after him from the inside. And, in any case, George Brooklyn was still alive at 11.30, when he was seen leaving the building by the front door. He had to get back, and Prinsep, if he killed him, must have been alive too until well after 11.30.” “And you can add to that the difficulty that George Brooklyn seems to have got back into the garden after 11.30, and that, where one man could enter unseen, so could two.” The inspector scratched his chin. “The whole thing is a puzzle,” he said. “But there’s one thing I’m sure of. It’s a much worse puzzle if you don’t assume that Walter Brooklyn was the murderer.” “Still, there’s nothing so dangerous as to simplify your problem by assuming what you cannot conclusively prove to be true. If I were a juryman, I certainly could not vote for a conviction on the evidence we have at present.” “But there’s no one else who could have done it.” “Oh, yes, there is. There’s all the population of London. I grant you we have at present no reason for suspecting any one else in particular. But that may be because we don’t know enough.” “Then what do you want me to do?” “Hunt, for all you’re worth, for further evidence. Don’t shut your eyes to the possibility that Walter Brooklyn may not be the murderer. Hunt for evidence of any kind, as if you were starting the case afresh.” “And, meanwhile, Walter Brooklyn remains in custody?” “Most certainly. There is presumptive evidence that he is the guilty party. But it’s nothing like a certainty. Remember that.”