He advanced to the window, and heard distinctly a foot on the grovel path that led to the verandah.

This sent him back to the hall in search of Dougal, whom he encountered in the passage.

That boy could certainly see in the dark, for he caught Dickson's wrist without hesitation.
"We've got Spittal in the wine-cellar," he whispered triumphantly.

"The kitchen door was barricaded, and when they tried it, it wouldn't open.
'Bide here,' says Dobson to Spittal, 'and we'll go round by another door and come back and open to ye.' So off they went, and by that time Peter Paterson and me had the barricade down.

As we expected, Spittal tries the key again and it opens quite easy.