Dr.Trenire's house was on the left-hand side of the street, as one walked up it, and it was the steep slope up of the garden behind it that made the old wall so fascinating.
To reach the garden from the house one had to pass through a cobbled yard, with the back wing of the house and a stable on one side of it, and a coach-house and another stable on the other.

The garden and the garden wall were at the end.

From the yard the wall ran up to a good height--to the children it seemed immense, as high as the tower of Babel, though were they to go back now and look at it I dare say they would find it quite insignificant, for walls have a curious way of decreasing an inch or two with every year one grows older.
To the children, though, its two chief charms were that it had a broad flat top on which one could sit and dangle one's legs over the abyss below, and that from the garden it was so low that by just walking over a flower-bed one could step right on to it, while from that eminence one could command a view of the back door, the side door, the stables, and all that went on in the yard.

So that, in addition to being cool and shady, it really was a most attractive and alluring spot.
A vine with a wealth of pretty leaves and long graceful tendrils covered the front of the stable and side of the house, and some years there would be a few bunches of little green grapes hanging amongst the leaves.

Through the open stable window, festooned by the vine, dear old Prue, Dr.Trenire's well-beloved and faithful mare, would thrust out her head and gaze dreamily at the life in the yard, or at nothing; and the children, if they were about, would rub her nose and fondle her lovingly, and bring her handfuls of grass, or carrots, or sugar.
Sometimes, too, "Pinkie," the yellow cat, would seat herself on the narrow sill of the stable window, close to Prue's cheek, until, finding the air too chilly, or the children too noisy, or sleep overcoming her, she would go inside and curl herself up on Prue's back for a nap.
To-day, though, neither Prue nor Pinkie were to be seen.
Apparently they were both indulging in an afternoon nap in the shady stable, for it really was a very hot day, and the sun fell full on the vine and the stable window.
Unfortunately it fell on the door too, and showed up a most inviting and enticing-looking spot where the sun had once raised a blister on the paint.
Every one will admit that there is a wonderful fascination about a nice soft paint-blister, and busy fingers had quickly peeled this one off, with the result that to-day there was a spot which made as good a target as any one could possibly desire, and just within range of their perch on the wall.