In that case, of course, the correct thing was to find the unexpected means.

But how could he outguess a band of trained criminals?
They would have foreseen far greater subtleties than any he could attempt.

They would be so keen that the best way to take them by surprise might be simply to step up to the house, ring the door bell and enter, if the door were opened.
The idea intrigued him at once.

They might be, and no doubt were, guarding every obscure cellar window, every skylight.

To trick them was impossible, but it was always possible to bluff any man--even John Mark and his followers.
Straight across the street marched Ronicky Doone and up the steps of the opposite house and rang the bell--not a timid ring, but two sharp pressures, such as would announce a man in a hurry, a brisk man who did not wish to be delayed.
He took only one precaution, pulling his hat down so that the black shadow of the brim would fall like a robber's mask across the upper part of his face.