There were thirty-eight; and, just as I
finished going through them, my eye fell on a scratching made with a
sharp point on the edge of the border. It was simply the number xxxviii
in Roman numerals. To cut the matter short, there was a similar note,
as I may call it, in each of the other lights; and that made it plain
to me that the glass-painter had had very strict orders from Abbot
Thomas about the inscription, and had taken pains to get it correct. “Well, after that discovery you may imagine how minutely I went over
the whole surface of the glass in search of further light. Of course, I
did not neglect the inscription on the scroll of Zechariah—‘Upon one
stone are seven eyes,’ but I very quickly concluded that this must
refer to some mark on a stone which could only be found _in situ_,
where the treasure was concealed. To be short, I made all possible
notes and sketches and tracings, and then came back to Parsbury to work
out the cipher at leisure. Oh, the agonies I went through! I thought
myself very clever at first, for I made sure that the key would be
found in some of the old books on secret writing. The _Steganographia_
of Joachim Trithemius, who was an earlier contemporary of Abbot Thomas,
seemed particularly promising; so I got that and Selenius’s
_Cryptographia_ and Bacon’s _de Augmentis Scientiarum_ and some more. But I could hit upon nothing. Then I tried the principle of the ‘most
frequent letter’, taking first Latin and then German as a basis. That
didn’t help, either; whether it ought to have done so, I am not clear. And then I came back to the window itself, and read over my notes,
hoping almost against hope that the Abbot might himself have somewhere
supplied the key I wanted. I could make nothing out of the colour or
pattern of the robes. There were no landscape backgrounds with
subsidiary objects; there was nothing in the canopies. The only
resource possible seemed to be in the attitudes of the figures. ‘Job,’
I read: ‘scroll in left hand, forefinger of right hand extended
upwards. John: holds inscribed book in left hand; with right hand
blesses, with two fingers. Zechariah: scroll in left hand; right hand
extended upwards, as Job, but with three fingers pointing up.’ In other
words, I reflected, Job has _one_ finger extended, John has _two_,
Zechariah has _three_. May not there be a numeral key concealed in
that? My dear Gregory,” said Mr Somerton, laying his hand on his
friend’s knee, “that _was_ the key. I didn’t get it to fit at first,
but after two or three trials I saw what was meant. After the first
letter of the inscription you skip _one_ letter, after the next you
skip _two_, and after that skip _three_. Now look at the result I got. I’ve underlined the letters which form words:

[D]R[E]VI[C]IOP[E]D[M]OO[M]SMV[I]V[L]IS[L]CAV[I]B[A]SB[A]TAO[V]T
[R]DI[I]EAM[R]L[E]SI[P]VSP[O]D[S]EE[I]RSE[T]T[A]AE[S]GIA[V]N[N]R
F[T]EEA[I]L[N]QD[P]VAI[V]M[T]LE[E]ATT[O]H[I]OO[N]VMC[A]A[T].H.Q.E. “Do you see it? ‘_Decem millia auri reposita sunt in puteo in at_. . .’
(Ten thousand [pieces] of gold are laid up in a well in …), followed by
an incomplete word beginning _at_. So far so good. I tried the same
plan with the remaining letters; but it wouldn’t work, and I fancied
that perhaps the placing of dots after the three last letters might
indicate some difference of procedure. Then I thought to myself,
‘Wasn’t there some allusion to a well in the account of Abbot Thomas in
that book the “_Sertum_”?’ Yes, there was: he built a _puteus in atrio_
(a well in the court). There, of course, was my word _atrio_. The next
step was to copy out the remaining letters of the inscription, omitting
those I had already used. That gave what you will see on this slip:

RVIIOPDOOSMVVISCAVBSBTAOTDIEAMLSIVSPDEERSETAEGIANRFEEALQDVAIMLEATTHOOVM
CA.H.Q.E. “Now, I knew what the three first letters I wanted were—namely,
_rio_—to complete the word _atrio_; and, as you will see, these are all
to be found in the first five letters. I was a little confused at first
by the occurrence of two _i’s_, but very soon I saw that every
alternate letter must be taken in the remainder of the inscription. You
can work it out for yourself; the result, continuing where the first
‘round’ left off, is this:

‘_rio domus abbatialis de Steinfeld a me, Thoma, qui posui custodem
super ea. Gare à qui la touche_’. “So the whole secret was out:

‘Ten thousand pieces of gold are laid up in the well in the court of
the Abbot’s house of Steinfeld by me, Thomas, who have set a guardian
over them. _Gare à qui la touche_.’

“The last words, I ought to say, are a device which Abbot Thomas had
adopted. I found it with his arms in another piece of glass at Lord
D——’s, and he drafted it bodily into his cipher, though it doesn’t
quite fit in point of grammar. “Well, what would any human being have been tempted to do, my dear
Gregory, in my place? Could he have helped setting off, as I did, to
Steinfeld, and tracing the secret literally to the fountain-head? I
don’t believe he could. Anyhow, I couldn’t, and, as I needn’t tell you,
I found myself at Steinfeld as soon as the resources of civilization
could put me there, and installed myself in the inn you saw. I must
tell you that I was not altogether free from forebodings—on one hand of
disappointment, on the other of danger. There was always the
possibility that Abbot Thomas’s well might have been wholly
obliterated, or else that someone, ignorant of cryptograms, and guided
only by luck, might have stumbled on the treasure before me. And
then”—there was a very perceptible shaking of the voice here—’I was not
entirely easy, I need not mind confessing, as to the meaning of the
words about the guardian of the treasure. But, if you don’t mind, I’ll
say no more about that until—until it becomes necessary. “At the first possible opportunity Brown and I began exploring the
place. I had naturally represented myself as being interested in the
remains of the abbey, and we could not avoid paying a visit to the
church, impatient as I was to be elsewhere. Still, it did interest me
to see the windows where the glass had been, and especially that at the
east end of the south aisle. In the tracery lights of that I was
startled to see some fragments and coats-of-arms remaining—Abbot
Thomas’s shield was there, and a small figure with a scroll inscribed
_Oculos habent, et non videbunt_ (They have eyes, and shall not see),
which, I take it, was a hit of the Abbot at his Canons. “But, of course, the principal object was to find the Abbot’s house. There is no prescribed place for this, so far as I know, in the plan of
a monastery; you can’t predict of it, as you can of the chapter-house,
that it will be on the eastern side of the cloister, or, as of the
dormitory, that it will communicate with a transept of the church. I
felt that if I asked many questions I might awaken lingering memories
of the treasure, and I thought it best to try first to discover it for
myself.