t it would not stir. She
went down on her knees to examine it. It had two padlocks, but neither
suited the key. Back to the kitchen, she sat down half bewildered and
looked around.

At that instant the little one came in, with a dimple in her rosy
cheeks and a cup of water in her hand.

Rotha took the water and tried to drink.

She was defeated once more. She put the keys into her pocket. Was she
ever to be one step nearer the heart of this mystery?

She rose wearily and walked out, forgetting to show the trick of the
bow to the little housekeeper who stood with a rueful pout in the
middle of the floor.

There was one thing left to do; with this other key, the key marked
with a cross, she could open Wilson's trunk in her father's cottage,
look at the papers, and perhaps discover wherein lay their interest
for Mrs. Garth. But first she must examine the two places in the road
referred to in the evidence at the trial.

In order to do this at once, Rotha turned towards Smeathwaite when she
left the blacksmith's cottage, and walked to the bridge.

The river ran in a low bed, and was crossed by the road at a sharp
angle. Hence the bridge lay almost out of sight of persons walking
towards it.

Fifty yards to the north of it was the spot where the woman Rushton
said she saw the murder. Fifty yards to the south of it was the spot
where the body was picked up next morning.

Rotha had reached the bridge, and was turning the angle of the road,
when she drew hastily back. Stepping behind a bush for further
concealment, she waited. Some one was approaching. It was Mrs. Garth.
The woman walked on until she came to within fifty paces of where
Rotha stood. Then she stopped. The girl observed her movements,
herself unseen.

Mrs. Garth looked about her to the north and south of the road and
across the fields on either hand. Then she stepped into the dike and
prodded the ground for some yards and kicked the stones that lay
there.

Rotha's breath came and went like a tempest.

Mrs. Garth stooped to look closely at a huge stone that lay by the
highway. Then she picked up a smaller stone and seemed to rub it on
the larger one, as if she wished to remove a scratch or stain.

Rotha was sure now.

Mrs. Garth stood on the very spot where the crime was said to have
been committed. This woman, then, and her son were at the heart of the
mystery. It was even as she had thought.

Rotha could hear the beat of her own heart. She plu