hless with
horror and despair. Then I recalled Thorndyke's calm, even confident,
attitude, and I hastened to remind her of it.

"There is one of your friends," I said, "who is still undismayed.
Thorndyke seems to anticipate no difficulties."

"And yet," she replied, "he is ready to consider a forlorn hope like
this. However, we shall see."

I could think of nothing more to say, and it was in gloomy silence that
we pursued our way down Inner Temple Lane and through the dark entries
and tunnel-like passages that brought us out, at length, by the
Treasury.

"I don't see any light in Thorndyke's chambers," I said, as we crossed
King's Bench Walk; and I pointed out the row of windows all dark and
blank.

"No; and yet the shutters are not closed. He must be out."

"He can't be after making an appointment with you and your father. It
is most mysterious. Thorndyke is so, very punctilious about his
engagements."

The mystery was solved, when we reached the landing, by a slip of paper
fixed by a tack on the iron-bound "oak."

"A note for P. B. is on the table," was the laconic message: on reading
which I inserted my key, swung the heavy door outward, and opened the
lighter inner door. The note was lying on the table and I brought it
out to the landing to read by the light of the staircase lamp.

"_Apologize to our friends,_" it ran, "_for the slight change of
programme. Norbury is anxious that I should get my experiments over
before the Director returns, so as to save discussion. He has asked me
to begin to-night and says he will see Mr. and Miss Bellingham here, at
the Museum. Please bring them along at once. I think some matters of
importance may transpire at the interview--J. E. T._"

"I hope you don't mind," I said apologetically, when I had read the
note to Ruth.

"Of course I don't," she replied. "I am rather pleased. We have so
many associations with the dear old Museum, haven't we?" She looked at
me for a moment with a strange and touching wistfulness and then turned
to descend the stone stairs.

At the Temple gate I hailed a hansom, and we were soon speeding
westward and north to the soft twinkle of the horse's bell.

"What are these experiments that Doctor Thorndyke refers to?" she asked
presently.

"I can only answer you vaguely," I replied. "Their object, I believe,
is to ascertain whether the penetrability of organic substances by the
X-rays becomes altered by age; whether, for in