“We’ll go and investigate in a moment, and watch the fun.”

This they did later on, finding the car turned turtle at the bottom of the hill, with three men standing around it in dismay.

Kennedy inquired what had happened, but neither would say much.

Yet, while they stood there, the second milk-laden waggon approached, passed, and went onward, its sleepy driver taking no notice of the five people at the roadside.

For half-an-hour Kennedy and Ella remained there in pretence of endeavouring to right the car, until they knew that the waggon, with its contents, was well out of harm’s way.

Then they remounted and returned to London, having, by their ingenious investigations and patient watching, saved the lives of thousands of Great Britain’s gallant boys in khaki.

Two days later Theodore Drost was taken suddenly ill with symptoms which puzzled his local doctor at Barnes. He spoke to Ortmann over the telephone, but the latter dared not risk a visit to Castelnau. Ella also heard from her father over the telephone when, that night, she returned to Stamfordham Mansions at the end of the “show.” She, knowing all she did, regarded a visit there as too dangerous, but rang up Kennedy at his air-station and guardedly informed him of the situation.

Five days later Theodore Drost lay dead of a malady to which the bespectacled doctor at Barnes gave a name upon his certificate, but of which he was really as ignorant as his own chauffeur.

But the curious part of the affair was that while Drost lay dead in the house, and the night before his burial, a mysterious fire broke out which gutted the place, a fact which no doubt must have been a great mystery to Ortmann and his friends.

The Metropolitan Fire Brigade still entertain very grave suspicions that it was due to an incendiary because of its fierceness; yet who, they ask themselves, could have had any evil design upon the property of the poor dead Dutch pastor?