Either is possible.

But whichever it may be, or if it is some third combination, it is down at Birlstone that we must seek the solution.

I know our man too well to suppose that he has left anything up here which may lead us to him." "Then to Birlstone we must go!" cried MacDonald, jumping from his chair.
"My word! it's later than I thought.

I can give you, gentlemen, five minutes for preparation, and that is all." "And ample for us both," said Holmes, as he sprang up and hastened to change from his dressing gown to his coat.

"While we are on our way, Mr.
Mac, I will ask you to be good enough to tell me all about it." "All about it" proved to be disappointingly little, and yet there was enough to assure us that the case before us might well be worthy of the expert's closest attention.