nvented
this way of making their plans."

"But who can it be?" asked Mugford. "It seems to me it's just like one
of those secret society things in Russia."

"So it is, and we must find out who they are," answered Diggory,
smacking his lips with great relish. "We'll see once more what can be
done by the Triple Alliance."

The more the three friends thought over the matter of the cipher letter,
the more their curiosity and interest were excited.

"I believe it's either Noaks or Mouler," said Mugford; "they were both
of them siding with Thurston, and trying to kick up a row at the
meeting."

"Oh, they'd neither of them have the sense to invent a thing like this,"
answered Jack. "They may be in it, but there's some one else besides."

Diggory scouted the idea of letting any other boys share their secret.
The honour of having discovered and exposed the plot must belong to the
Triple Alliance alone, and it must be said that they had accomplished
their task unaided by any outsiders.

That evening and the following day the greater portion of their free
time was spent in discussing the great question as to what should be
done. The cipher note evidently had direct connection with the
attack on Browse, but the translation of the letter was in itself like
finding a key without knowing the whereabouts of the lock which it
fitted. The question was, by whom and for whom it had been written.

Afternoon school was just over, and the three friends were standing
warming their feet on a hot-water pipe, discussing the likelihood of
making any other discoveries which might tend to throw more light on the
subject, when suddenly a happy thought entered the head of Jack Vance.

"Look here, Diggory. You said you found this note in a crack in the
wall under one of the grub-room windows, and that you thought some
fellows were using it as a sort of post-office. Well, have you
been there to see if anything's been put there since?"

"No!" cried Diggory. "Good idea! I'll go now at once."

He walked quickly out of the room, and came back a few moments later at
a run.

"I've got one!" he exclaimed, in a low, eager tone. "Don't let any one
see; come to my desk."

The note this time was very brief:--

ZUGVIGVZFMWVIGSVKZE.

Diggory hastily fished out his double alphabet, wrote down the proper
letters as Jack read out those on the paper, and in a few seconds the
translation was complete, and read as follows:--

"_Afte