one from walking in.

"now i will give you the evidence of susan tarlton, who is

the only person who can say anything positive about the

matter. it was in the forenoon, between eleven and twelve.

she was engaged at the moment in hanging some curtains in

the upstairs front bedroom. professor coram was still in

bed, for when the weather is bad he seldom rises before

midday. the housekeeper was busied with some work in the

back of the house. willoughby smith had been in his

bedroom, which he uses as a sitting-room; but the maid heard

him at that moment pass along the passage and descend to the

study immediately below her. she did not see him, but she

says that she could not be mistaken in his quick, firm

tread. she did not hear the study door close, but a minute

or so later there was a dreadful cry in the room below. it

was a wild, hoarse scream, so strange and unnatural that it

might have come either from a man or a woman. at the same

instant there was a heavy thud, which shook the old house,

and then all was silence. the maid stood petrified for a

moment, and then, recovering her courage, she ran

downstairs. the study door was shut, and she opened it.

inside young mr. willoughby smith was stretched upon the

floor. at first she could see no injury, but as she tried

to raise him she saw that blood was pouring from the

underside of his neck. it was pierced by a very small but

very deep wound, which had divided the carotid artery. the

instrument with which the injury had been inflicted lay upon

the carpet beside him. it was one of those small

sealing-wax knives to be found on old-fashioned

writing-tables, with an ivory handle and a stiff blade.

it was part of the fittings of the professor's own desk.

"at first the maid thought that young smith was already

dead, but on pouring some water from the carafe over his

forehead he opened his eyes for an instant. 'the

professor,' he murmured -- 'it was she.' the maid is

prepared to swear that those were the exact words. he tried

desperately to say something else, and he held his right

hand up in the air. then he fell back dead.

"in the meantime the housekeeper had also arrived upon the

scene, but she was just too late to catch the young man's

dying words. leaving susan with the body, she hurried to

the professor's room. he was sitting up in bed horribly

agitated, for he had heard enough to convince him that

something terrible had occurred. mrs. marker is prepared to

swear that the professor was still in his night-clothes,

and, indeed, it was impossible for him to dress without the

help of mortimer, whose orders were to come at twelve

o'clock. the professor declares that he heard the distant

cry, but that he knows nothing more. he can give no

explanation of the young man's last words, 'the professor --

it was she,' but imagines that they were the outcome of

delirium. he believes that willoughby smith had not an

enemy in the world, and can give no reason for the crime.

his first action was to send mortimer the gardener for the

local police. a little later the chief constable sent for me.

nothing was moved before i got there, and strict orders were

given that no one should walk upon the paths leading to the

house. it was a splendid chance of putting your theories

into practice, mr. sherlock holmes. there was really nothing

wanting."

"except mr. sherlock holmes," said my companion, with a

somewhat bitter smile. "well, let us hear about it. what

sort of job did you make of it?"

"i must ask you first, mr. holmes, to glance at this rough

plan, which will give you a general idea of the position of

the professor's study and the various points of the case.

it will help you in following my investigation."

he unfolded the rough chart, which i here reproduce, and he

laid it across holmes's knee. i rose, and, standing behind

holmes, i studied it over his shoulder.

{graphic}

"it is very rough, of course, and it only deals with the

points which seem to me to be essential. all the rest you

will see later for yourself. now, first of all, presuming

that the assassin entered the house, how did he or she come

in? undoubtedly by the garden path and the back door, from

which there is direct access to the study. any other way

would have been exceedingly complicated. the escape must

have also been made along that line, for of the two other

exits from the room one was blocked by susan as she ran

downstairs and the other leads straight to the professor's

bedroom. i therefore directed my attention at once to the

garden path, which was saturated with recent rain and would

certainly show any footmarks.

"my examination showed me that i was dealing with a cautious

and expert criminal. no footmarks were to be found on the

path. there could be no question, however, that someone had

passed