"The probability is that neither has any suspicion of being watched--the whole thing's so clever that they probably believe themselves safe.

Of course, mind you, this man Rayner may be as innocent as you or I.But against her, on the facts of that photograph affair, there's a _prima facie_ case.

Only--don't let's spoil things by undue haste or rashness.

I've thought things out a good deal, and we can do a lot, you and me, before going to the police, though I don't think it 'ud do any harm to tell this man Chettle, supposing he were here--because his discovery of that photo is the real thing." "What can we do, then ?" asked Allerdyke.
"Make use of the two Gaffneys," answered Appleyard without hesitation.
"They're smart chaps---real keen 'uns.

We want to find out who Rayner is; what his connection, if any, with Miss Slade, alias Mrs.Marlow, is; who she is, and why she goes under two names.