“Jolly clever idea if it works all right,” said Walter slowly.  “I can see Mr. Deede Dawson is a man who needs watching.  And I suppose we had better be on the look-out at the Abbey tomorrow night?”

“Evening,” corrected Dunn.  “It’s planned for the dinner-hour.”

“Right,” said Walter.  “We shall see some crowded hours tomorrow, I expect.  Well, it’s like this, as I understand it—­we had better be sure everything is quite clear.  Their idea is that you will meet and murder Rupert Dunsmore, who they have no notion is really your own self, at Brook Bourne Spring at four tomorrow afternoon, and the unknown somebody who is behind all this business will be in hiding there to make sure you do your work properly.  Our idea is to watch all the roads leading to Ottam’s Wood and to have men in ambush near the spring to seize any one hiding there at that time.  Then we shall know who is at the bottom of all these plots and shall be able to smash the whole conspiracy.  In addition, Deede Dawson and this other man you speak of, Allen, are going to break into the Abbey tomorrow evening and we are to be ready for them and catch them in the act?”

“Yes,” said Dunn, “that’s the idea; you can manage all right?”

“Oh, yes,” answered Walter.  “It’s all simple enough—­you’ve planned it out so jolly well there’s nothing much left for me to do.  And I don’t see what you’re nervous about; there’s nothing that can go wrong very well—­your plans are perfect, I think.”

“It’s easy enough to make plans when you know just what the other side are going to do,” observed Dunn.  “There’s one point more.  Miss Cayley—­I mentioned her in one of the notes I sent you through Burns.”

“Yes, I remember—­Deede Dawson’s step-daughter,” said Walter.  “I suppose she is in it?”

“She is not; she knows nothing,” declared Dunn vehemently.

“But it was she who took away poor Charley’s body, wasn’t it?” asked Walter.  “But for that you would have had evidence enough to act on at once, wouldn’t you?”

“She did not know what she was doing,” Dunn replied.  “And now she is in danger herself.  I am convinced Deede Dawson is growing afraid of her, he dropped hints; I’m sure he is planning something, perhaps he means to murder her as well.  So besides these other arrangements I want to see that there’s a trustworthy man watching here.  I don’t anticipate that there’s any immediate danger—­it’s almost certain that if he means anything he will wait till he sees how this other business is turning out.  But I want some one trustworthy to be at hand in case of need.  You will see to that?”

“Oh, yes, I can spare Simmonds; I’ll send him,” answered Walter.  “Though, I must say, my dear chap, I don’t think I should trouble much about that young lady.  But it can be easily managed, in fact everything you want me to do is easy enough; I only wish some of it was a bit difficult or dangerous.”