he authorities had been altogether idle.
Inspector Merrick spent most of his time traveling up and down the line
by slow local trains on the off-chance of hearing some significant
incident that might lead to a clue. There was one thing obvious--the
bullion boxes must have been thrown off the train at some spot arranged
between the active thief and his confederates. For this was too big a
thing to be entirely the work of one man. Some of the gang must have
been waiting along the line in readiness to receive the boxes and carry
them to a place of safety. By this time, no doubt, the boxes themselves
had been destroyed; but eight thousand pounds in gold takes some moving,
and probably a conveyance, a motor for choice, had been employed for
this purpose. But nobody appeared to have seen or heard anything
suspicious on the night of the murder; no prowling gamekeeper or watcher
had noticed anything out of the common. Along the Essex and Norfolk
marshes, where the Grand Coast Railway wound along like a steel snake,
they had taken their desolate and dreary way. True, the dead body of a
man had been found in the fowling nets up in the mouth of the Little
Ouse, and nobody seemed to know who he was; but there could be no
connection between this unhappy individual and the express criminal.
Merrick shook his head as he listened to this from a laborer in a
roadside public house where he was making a frugal lunch on bread and
cheese.

"What do you call fowling nets?" Merrick asked.

"Why, what they catches the birds in," the rustic explained. "Thousands
and thousands of duck and teel and widgeon they catches at this time of
year. There's miles of nets along the road--great big nets like fowl
runs. Ye didn't happen to see any on 'em as ye came along in the train?"

"Now I come to think of it, yes," Merrick said thoughtfully. "I was
rather struck by all that netting. So they catch sea birds that way?"

"Catches 'em by the thousand, they does. Birds fly against the netting
in the dark and get entangled. Ducks they get by 'ticing 'em into a sort
of cage with decoys. There's some of 'em stan's the best part of half a
mile long. Covered in over the top like great cages. Ain't bad sport,
either."

Merrick nodded. He recollected it all clearly now. He recalled the wide,
desolate mud flats running right up to the railway embankment for some
miles. At high tide the mud flats were under water, and out of these the
great mass of network rose