Clarette announced her determination to follow her husband to Ostend, and perhaps she did so, as they did not see her again.
It was on Sunday, the twentieth of December, that the Battle of the Dunes began and the flames of war burst out afresh.

The dunes lay between the North Sea and the Yser River in West Flanders and consisted of a stretch of sandy hillocks reaching from Coxyde to Nieuport les Bains.

The Belgians had entrenched these dunes in an elaborate and clever manner, shoveling the sand into a series of high lateral ridges, with alternate hollows, which reached for miles along the coast.

The hollows were from six to eight feet deep, affording protection to the soldiers, who could nevertheless fire upon the enemy by creeping up the sloping embankments until their heads projected sufficiently to allow them to aim, when they could drop back to safety.
In order to connect the hollows one with another, that an advance or retreat might be made under cover, narrow trenches had been cut at intervals diagonally through the raised mounds of sand.

Military experts considered this series of novel fortifications to be practically impregnable, for should the enemy defile through one of the cross passages into a hollow where the Allies were gathered, they could be picked off one by one, as they appeared, and be absolutely annihilated.
Realizing this, the Germans had not risked an attack, but after long study of the defences had decided that by means of artillery they might shell the Belgians, who held the dunes, and destroy them as they lay in the hollows.