"Ohs!" and "Ahs!" slipped from my open mouth. The o

! is it

faithful soul by reading her the letter from

oubt," said I, shr

dmaid, "if it isn't from the devil, i

hat it was the work of a practical joker. My adventure was well known. The newspapers had given it in full

mselves. Their chief security would lie in keeping their presence there unknown. They must have realized that such a challenge from them would only arouse the police to renewed activity. Dynamite or melinite would soon open an entrance to their fortre

would attach no importance to it. However, I did not destroy it, but locked it in my desk for safe keeping. If mo

ignation from the force. Of the mysterious chauffeur or chauffeurs, nothing more was heard. I knew that our own government agents, as well as foreign ones, were keeping keen watch over all the roads and rivers, all the lakes and the coasts of America. Of course, the size of the country made any close supervision impossible; but these twin inventors had not before chosen secluded and unfrequented spots in which t

personage could not find one better than the Great Eyrie!" But, of course, a boat could not get there,

two men who looked at me with a certain keenness. Not knowing them, I took no notice; and if

on me in the street. They stood constantly, perhaps a hundred steps from my

sure?"

o the house, these men came slipping along in your footsteps,

st be m

not,

hese two men, you

wou

ve the very spirit for a detective. I mu

need spectacles to recognize people. Someone is spying on you, that'

y her. "And when my men get after them, we shall s

cement very seriously. I added, however, "When I go ou

ll be be

self at nothing. "If I see them again," she added,

f I allowed her to run on, she would end by being sure that Bee

ld servant had made much of nothing, as usual. But on the morning of the twenty-second of June, after rushing upstair

t is

are

n anything but the web she

two s

e wonderf

n front of our windows! Watching th

edge of the shade, so as not to give an

the day, with slouched hats, heavy woolen suits, stout walking shoes and sticks in hand. Undoubtedly, they were staring persis

se are the same m

s,

lf, I was presumably too well known to them. To address them directly would probably be of no use. But that very day, one of our best men should

it was there that I was bound, as usual. If they accompanied me I might

ned peeping from the window, I went down stair

were no lo

at time on, indeed, neither my old servant nor I saw them again before the house, nor did I encoun

n in my identity. Having obtained a good look at me, they now followed me no more. So in the end,

that of the general public in the previous mysteries of the automobile and the boat. The Washington Ev

own. It deserves wider knowledge, and doubtless will have it here

o outlet. What it loses by evaporation, it regains from

ts which surround it. Shut in among the mountains, it can be reached only by narrow and rocky gorges. Sever

high winds, beat upon its banks with fury, and the houses near at hand are often deluged with spray as if with the downpour of a hurricane.

ition to the dozen or so of little steamers which serve the traffic of the lake. Beyond the circle of the mountains

ary for the understanding of the remark

noticed a strange upheaval in the waters of the lake. Sometimes it rises as if a wave surged up from its depths.

ts have been swept beyond all control. Sometimes they have bee

to seismic forces, to some volcanic action beneath the lake; but this hypothesis had to be rejected when it was recognized that the disturbance was not confined to one locality, but spread itself over the e

ust have come there from outside. Lake Kirdall, however, has no connection with any other waters. If this lake were situated near any of the oceans, there might be subterranean canals; but in the center of America, and at the he

ed a boat, The Protector, which could go on the water, under the water, and also upon land. Built by an inventor named Lake, supplied with two motors, an electric one of seventy-five hor

h degree of perfection, there remains as before the question how could it have reached Lake Kirdall? The lak

ooner "Markel" while speeding with all sails set, came into violent collision with something just below the water level. There was no shoal nor rock near; for the lake in this part is eighty

p on shore, an examination showed that she had rece

a submarine boat which darts about beneath the su

e get there? But why is it there? Why does it never come to the surface? What reason has it

riking suggestion: "After the mysterious automobile, came

due to the genius of the same inventor, and t