Three interlocking circles on the chest

The snow has closed the pass again, so the carrier who brought the post up the valley left the sacks at the bottom of the lane and went back down before noon. I have had the kitchen boy carry up what he could. Your letter came third from the top, damp at one corner, and I read it twice standing by the range before I could take my coat off. You were right about the ledger. Father's three hand-drawn plans for the east wing overlap exactly as you said, and the rooms they describe cannot all have existed at once.

I spent the afternoon with a lamp and a pair of compasses, tracing each plan onto oiled paper. Where the three circles he drew for the courtyard fountain cross one another, there is a small lens of space that belongs to none of them. I measured it four times. Mrs Harrow, who has kept this house longer than I have been alive, watched me from the doorway and said only that the inn was built by a man who liked his arithmetic to close, and that it never quite did.

I am sending you the tracing with this letter. Lay it over the drawings on your own table and look at the centre where the rings meet. If the lens is where I think it is, the wall behind the linen press is not a wall at all, and the room beyond it is the only one on the plan that Father never bothered to name.

Tell no one yet. The pass will open in a week, and I would rather be right with you beside me than clever on my own.

Yours in cold ink, Helena