reams that night were of a mighty
chain of redoubts and masked batteries couching _perdus_ among the
sand-dunes of desolate islets; built, coral-like, by infinitely slow
and secret labour; fed by lethal cargoes borne in lighters and in
charge of stealthy mutes who, one and all, bore the likeness of
Grimm. I was up and away at daylight (the weather mild and showery),
meeting some navvies on my way back to the road, who gave me good
morning and a stare. On the bridge I halted and fell into torments of
indecision. There was so much to do and so little time to do it in.
The whole problem seemed to have been multiplied by seven, and the
total again doubled and redoubled--seven blue lines on land, seven
dotted lines on the sea, seven islands in the offing. Once I was near
deciding to put my pretext into practice, and cross to Langeoog; but
that meant missing the rendezvous, and I was loth to do that.

At any rate, I wanted breakfast badly; and the best way to get it,
and at the same time to open new ground, was to walk to Dornum. Then
I should find a blue line called the _Neues Tief_ leading to
Dornumersiel, on the coast. That explored, I could pass on to Nesse,
where there was another blue line to Nessmersiel. All this was on the
way to Norden, and I should have the railway constantly at my back,
to carry me there in the evening. The last train (my time-table told
me) was one reaching Norden at 7.15 p.m. I could catch this at Hage
Station at 7.5.

A brisk walk of six miles brought me, ravenously hungry, to Dornum.
Road and railway had clung together all the time, and about half-way
had been joined on the left by a third companion in the shape of a
puny stream which I knew from the map to be the upper portion of
Neues Tief. Wriggling and doubling like an eel, choked with sedges
and reeds, it had no pretensions to being navigable. At length it
looped away into the fens out of sight, only to reappear again close
to Dornum in a much more dignified guise.

There was no siding where the railway crossed it, but at the town
itself, which it skirted on the east, a towpath began, and a piled
wharf had been recently constructed. Going on to this was a red-brick
building with the look of a warehouse, roofless as yet, and with
workmen on its scaffolds. It sharpened the edge of my appetite.

If I had been wise I should have been content with a snack bought at
a counter, but a thirst for hot coffee and clues induced me to repeat
the e