ng time."

"Your invitation," Mr. Sabin remarked, "is most agreeable. But your
suggestion is, to say the least of it, nebulous. I do not see what is to
prevent your all having supper with me to-morrow evening."

Lady Carey laughed as she rose, and stretched out her hand for her
cloak.

"To-morrow evening," she said, "is a long way off. Let us make sure of
to-night--before the Prince changes his mind."

Mr. Sabin bowed low.

"To-night by all means," he declared. "But my invitation remains--a
challenge!"

CHAPTER XXXI

The Prince, being host, arranged the places at his supper-table. Mr.
Sabin found himself, therefore, between Lady Carey and a young German
attache, whom they had met in the ante-room of the restaurant. Lucille
had the Prince and Mr. Brott on either side of her.

Lady Carey monopolised at first the greater part of the conversation.
Mr. Sabin was unusually silent. The German attache, whose name was Baron
von Opperman, did not speak until the champagne was served, when he
threw a bombshell into the midst of the little party.

"I hear," he said, with a broad and seraphic smile, "that in this hotel
there has to-day a murder been committed."

Baron von Opperman was suddenly the cynosure of several pairs of eyes.
He was delighted with the success of his attempt towards the general
entertainment.

"The evening papers," he continued, "they have in them news of a sudden
death. But in the hotel here now they are speaking of something--what
you call more--mysterious. There has been ordered an examination
post-mortem!"

"It is a case of poisoning then, I presume?" the Prince asked, leaning
forward.

"It is so supposed," the attache answered. "It seems that the doctors
could find no trace of disease, nothing to have caused death. They
were not able to decide anything. The man, they said, was in perfect
health--but dead."

"It must have been, then," the Prince remarked, "a very wonderful
poison."

"Without doubt," Baron Opperman answered.

The Prince sighed gently.

"There are many such," he murmured. "Indeed the science of toxicology
was never so ill-understood as now. I am assured that there are many
poisons known only to a few chemists in the world, a single grain of
which is sufficient to destroy the strongest man and leave not the
slightest trace behind. If the poisoner be sufficiently accomplished he
can pursue his--calling without the faintest risk of detection."

Mr. Sabin sipped his