'Certainly, sir.'

We followed the guard, and the moment he had imparted his news there
was a suppressed scream in the carriage. Instantly a lady came out,
followed by a florid-faced gentleman, who scowled at the guard. We
entered the now empty compartment, and Kombs said:

'We would like to be alone here until we reach Brewster.'

'I'll see to that, sir,' answered the guard, locking the door.

When the official moved away, I asked my friend what he expected to
find in the carriage that would cast any light on the case.

'Nothing,' was his brief reply.

'Then why do you come?'

'Merely to corroborate the conclusions I have already arrived at.'

'And might I ask what those conclusions are?'

'Certainly,' replied the detective, with a touch of lassitude in his
voice. 'I beg to call your attention, first, to the fact that this
train stands between two platforms, and can be entered from either
side. Any man familiar with the station for years would be aware of
that fact. This shows how Mr. Kipson entered the train just before it
started.'

'But the door on this side is locked,' I objected, trying it.

'Of course. But every season ticket-holder carries a key. This
accounts for the guard not seeing him, and for the absence of a
ticket. Now let me give you some information about the influenza. The
patient's temperature rises several degrees above normal, and he has a
fever. When the malady has run its course, the temperature falls to
three-quarters of a degree below normal. These facts are unknown to
you, I imagine, because you are a doctor.'

I admitted such was the case.

'Well, the consequence of this fall in temperature is that the
convalescent's mind turns towards thoughts of suicide. Then is the
time he should be watched by his friends. Then was the time Mr. Barrie
Kipson's friends did _not_ watch him. You remember the 21st, of
course. No? It was a most depressing day. Fog all around and mud under
foot. Very good. He resolves on suicide. He wishes to be unidentified,
if possible, but forgets his season ticket. My experience is that a
man about to commit a crime always forgets something.'

'But how do you account for the disappearance of the money?'

'The money has nothing to do with the matter. If he was a deep man,
and knew the stupidness of Scotland Yard, he probably sent the notes
to an enemy. If not, they may have been given to a friend. Nothing is
more calculated to prepare the mind for self-destru