ite trivial incident takes place. He had felt
sure that this lorry standing at the mill door was that which had passed
him on the bridge, and which he had followed down the lane. But now
he saw it wasn't. He had noted, idly but quite distinctly, that the
original machine was No. 4. This one had a precisely similar plate, but
it bore the legend "The Landes Pit-Prop Syndicate, No. 3."

Though the matter was of no importance, Merriman was a little intrigued,
and he looked more closely at the vehicle. As he did so his surprise
grew and his trifling interest became mystification. The lorry was the
same. At least there on the top was the casting, just as he had seen it.
It was inconceivable that two similar lorries should have two identical
castings arranged in the same way, and at the same time and place. And
yet, perhaps it was just possible.

But as he looked he noticed a detail which settled the matter. The
casting was steadied by some rough billets of wood. One of these billets
was split, and a splinter of curious shape had partially entered a bolt
hole. He recalled now, though it had slipped from his memory, that he
had noticed that queer-shaped splinter as the lorry passed him on the
bridge. It was therefore unquestionably and beyond a shadow of doubt the
same machine.

Involuntarily he stopped and stood staring at the number plate,
wondering if his recollection of that seen at the bridge could be at
fault. He thought not. In fact, he was certain. He recalled the shape of
the 4, which had an unusually small hollow in the middle. There was
no shadow of doubt of this either. He remained motionless for a few
seconds, puzzling over the problem, and was just about to remark on it
when the girl broke in hurriedly.

"Father will be in the office," she said, and her voice was sharpened as
from anxiety. "Won't you come and see him about the petrol?"

He looked at her curiously. The smile had gone from her lips, and
her face was pale. She was frowning, and in her eyes there showed
unmistakable fear. She was not looking at him, and his gaze followed the
direction of hers.

The driver had come out of the shed, the same dark, aquiline-featured
man as had passed him on the bridge. He had stopped and was staring at
Merriman with an intense regard in which doubt and suspicion rapidly
changed to hostility. For a moment neither man moved, and then once
again the girl's voice broke in.

"Oh, there is father," she cried, with bare