kneel beside him。 This lavatory is lit by the glass door； and； when
the door was open； the light which penetrated was sufficient to light
it perfectly。 Monsieur de Marquet and Monsieur Joseph Rouletabille
knelt down on the threshold； and the young man pointed to a spot on
the pavement。
〃The stones of the lavatory have not been washed by Daddy Jacques
for some time；〃 he said； 〃that can be seen by the layer of dust that
covers them。 Now； notice here； the marks of two large footprints
and the black ash they left where they have been。 That ash is
nothing else than the charcoal dust that covers the path along which
you must pass through the forest； in order to get directly from
Epinay to the Glandier。 You know there is a little village of
charcoal…burners at that place； who make large quantities of
charcoal。 What the murderer did was to come here at midday； when
there was nobody at the pavilion； and attempt his robbery。〃
〃But what robbery？ … Where do you see any signs of robbery？ What
proves to you that a robbery has been committed？〃 we all cried at
once。 〃What put me on the trace of it；〃 continued the journalist。。。
〃Was this？〃 interrupted Monsieur de Marquet； still on his knees。
〃Evidently；〃 said Rouletabille。
And Monsieur de Marquet explained that there were on the dust of
the pavement marks of two footsteps； as well as the impression；
freshly…made； of a heavy rectangular parcel； the marks of the cord
with which it had been fastened being easily distinguished。
〃You have been here； then； Monsieur Rouletabille？ I thought I had
given orders to Daddy Jacques； who Was left in charge of the
pavilion； not to allow anybody to enter。〃
〃Don't scold Daddy Jacques； I came here with Monsieur Robert Darzac。〃
〃Ah； … Indeed！〃 exclaimed Monsieur de Marquet； disagreeably； casting
a side…glance at Monsieur Darzac； who remained perfectly silent。
〃When I saw the mark of the parcel by the side of the footprints； I
had no doubt as to the robbery；〃 replied Monsieur Rouletabile。 〃The
thief had not brought a parcel with him； he had made one here … a
parcel with the stolen objects； no doubt； and he put it in this
corner intending to take it away when the moment came for him to
make his escape。 He had also placed his heavy boots beside the
parcel； … for； see … there are no marks of steps leading to the
marks left by the boots； which were placed side by side。 That
accounts for the fact that the murderer left no trace of his steps
when he fled from The Yellow Room； nor any in the laboratory； nor in
the vestibule。 After entering The Yellow Room in his boots； he took
them off； finding them troublesome； or because he wished to make as
little noise as possible。 The marks made by him in going through
the vestibule and the laboratory were subsequently washed out by
Daddy Jacques。 Having； for some reason or other； taken off his
boots； the murderer carried them in his hand and placed them by the
side of the parcel he had made； … by that time the robbery had been
accomplished。 The man then returned to The Yellow Room and slipped
under the bed； where the mark of his body is perfectly visible on
the floor and even on the mat； which has been slightly moved from
its place and creased。 Fragments of straw also； recently torn； bear
witness to the murderer's movements under the bed。〃
〃Yes； yes； … we know all about that；〃 said Monsieur de Marquet。
〃The robber had another motive for returning to hide under the bed；〃
continued the astonishing boy…journalist。 〃You might think that he
was trying to hide himself quickly on seeing； through the vestibule
window； Monsieur and Mademoiselle Stangerson about to enter the
pavilion。 It would have been much easier for him to have climbed
up to the attic and hidden there； waiting for an opportunity to get
away； if his purpose had been only flight。 … No！ No！ … he had to
be in The Yellow Room。〃
Here the Chief intervened。
〃That's not at all bad； young man。 I compliment you。 If we do not
know yet how the murderer succeeded in getting away； we can at any
rate see how he came in and committed the robbery。 But what did he
steal？〃
〃Something very valuable；〃 replied the young reporter。
At that moment we heard a cry from the laboratory。 We rushed in
and found Monsieur Stangerson； his eyes haggard； his limbs
trembling； pointing to a sort of bookcase which he had opened； and
which； we saw； was empty。 At the same instant he sank into the
large armchair that was placed before the desk and groaned； the
tears rolling down his cheeks； 〃I have been robbed again！ For God's
sake； do not say a word of this to my daughter。 She would be more
pained than I am。〃 He heaved a deep sigh and added； in a tone I
shall never forget： 〃After all； what does it matter； … so long as
she lives！〃
〃She will live！〃 said Monsieur Darzac； in a voice strangely touching。
〃And we will find the stolen articles；〃 said Monsieur Dax。 〃But
what was in the cabinet？〃
〃Twenty years of my life；〃 replied the illustrious professor sadly；
〃or rather of our lives … the lives of myself and my daughter！ Yes；
our most precious documents； the records of our secret experiments
and our labours of twenty years were in that cabinet。 It is an
rreparable loss to us and； I venture to say； to science。 All the
processes by which I had been able to arrive at the precious proof
of the destructibility of matter were there … all。 The man who came
wished to take all from me； … my daughter and my work … my heart
and my soul。〃
And the great scientist wept like a child。
We stood around him in silence； deeply affected by his great
distress。 Monsieur Darzac pressed closely to his side； and tried
in vain to restrain his tears … a sight which； for the moment；
almost made me like him； in spite of an instinctive repulsion which
his strange demeanour and his inexplicable anxiety had inspired me。
Monsieur Rouletabille alone； … as if his precious time and mission
on earth did not permit him to dwell in the contemplation on human
suffering … had； very calmly； stepped up to the empty cabinet and；
pointing at it； broke the almost solemn silence。 He entered into
explanations； for which there was no need； as to why he had been led
to believe that a robbery had been committed； which included the
simultaneous discovery he had made in the lavatory； and the empty
precious cabinet in the laboratory。 The first thing that had struck
him； he said； was the unusual form of that piece of furniture。 It
was very strongly built of fire…proof iron； clearly showing that it
was intended for the keeping of most valuable objects。 Then he
noticed that the key had been left in the lock。 〃One does not
ordinarily have a safe and leave it open！〃 he had said to himself。
This little key； with its brass head and complicated wards； had
strongly attracted him； … its presence had suggested robbery。
Monsieur de Marquet appeared to be greatly perplexed； as if he did
not know whether he ought to be glad of the new direction given to
the inquiry by the young reporter； or sorry that it had not been
done by himself。 In our profession and for the general welfare； we
have to put up with such mortifications and bury selfish feelings。
That was why Monsieur de Marquet controlled himself and joined his
compliments with those of Monsieur Dax。 As for Monsieur Rouletabille；
he simply shrugged his shoulders and said： 〃There's nothing at all
in that！〃 I should have liked to box his ears； especially when he
added： 〃You will do well； Monsieur； to ask Monsieur Stangerson who
usually kept that key？〃
〃My daughter；〃 replied Monsieur Stangerson； 〃she was never without it。
〃Ah！ then that changes the aspect of things which no longer
corresponds with Monsieur Rouletabille's ideas！〃 cried Monsieur de
Marquet。 〃If that key never left Mademoiselle Stangerson； the
murderer must have waited for her in her room for the purpose of
stealing it； and the robbery could not have been committed until
after the attack had been made on her。 But after the attack four
persons were in the laboratory！ I can't make it out！〃
〃The robbery；〃 said the reporter； 〃could only have been committed
before the attack upon Mademoiselle Stangerson in her room。 When
the murderer entered the pavilion he already possessed the
brass…headed key。〃
〃That is impossible；〃 said Monsieur Stangerson in a low voice。
〃It is quite possible； Monsieur； as this proves。〃
And the young rascal drew a copy of the 〃Epoque〃 from his pocket；
dated the 21st of October （I recall the fact that the crime was
committed on the night between the 24th and 25th）； and showing us
an advertisement； he read：
〃'Yesterday a black satin reticule was lost in the Grands Magasins
de la Louvre。 It contained； amongst other things； a small key with
a brass head。 A handsome reward will be given to the person who
has found it。 This person must write； poste restante； bureau 40； to
this address： M。 A。 T。 H。 S。 N。' Do not these letters suggest
Mademoiselle Stangerson？〃 continued the reporter。 〃The 'key with
a brass head' … is not this the key？ I always read advertisements。
In my business； as in yours； Monsieur； one should always read the
personals。' They are often the keys to intrigues； that are not
lways brass…headed； but which are none the less interesting。 This
dvertisement interested me specially； the woman of the key surrounded
it with a kind of mystery。 Evidently she valued the key； since she
promised a big reward for its restoration！ And I thought on these
six letters： M。 A。 T。 H。 S。 N。 The first four at once pointed to
a Christian name； evidently I said Math is Mathilde。 But I could
make nothing of the two last letters。 So I threw the journal aside
and occupied myself with other matters。 Four days later； when the
evening paper appeared with enormous head…lines announcing the murder
of Mademoiselle Stangerson； the letters in the advertisement
mechanically recurred to me。 I had forgotten the two last letters；
S。 N。 When I saw them again I could not help exclaiming；
'Stangerson！' I jumped into a cab and rushed into the bureau No。
40； asking： 'Have you a letter addressed to M。 A。 T。 H。 S。 N。？'
The clerk re