His eye fell upon a strange door with curious marks burnt upon its panels apparently by hot irons.

There were circles complete and circles that stopped half-way, together with letters of some unknown language arranged mostly in triangles.
This door fixed the lad's attention with a certain curious fascination.

He longed to touch it and see whether it opened, but for the moment he was too much afraid of his guide's return to summon him into the presence of the marshal.
He listened intently.

Surely he heard a low sound, like the wind in a distant keyhole--or, as it might be (and it seemed more like it), the moaning of a child in pain, it knows not why.
The heart of the youth gave a sudden leap.

It came to him that he had hit upon the hiding-place of Margaret Douglas, the heiress of the great province of Galloway.