d? We are quite safe, Lady Elza."

She and Tarrano were alone in the boat. It was long and very narrow,
with its sides no more than a foot above the water. Tarrano sat at its
chemical mechanism. A boat familiar to us of Earth. A small
chemical-electric generator. The explosion of water in a little tank,
with the resultant gases ejected through a small pipe projecting under
the surface at its stern. The boat swept forward smoothly, rapidly and
almost silently, with a stream of the gas bubbles coming to the surface
in its wake.

"Quite safe, Lady Elza."

She saw that Tarrano's face was blackened with grime. His garments were
burned, and hers were also. He was disheveled, but his manner was as
imperturbable as ever. He made her comfortable on the cushions in the
boat; drew a robe closer around her against the rush of the night air.

Elza was unhurt. She saw now, with clarifying senses, that they were
plying along a narrow river. Banks of foliage on each side; the auroral
lights in the sky; occasionally on the hillsides along the river, the
dim outlines of a house.

It was all a trifle unreal--like looking through a sunglass that was
darkened--for around the boat hung always a vague pall of gloom. Tarrano
spoke of it.

"Our isolation barrage. It is very weak, but the best I can
contrive. From these hills the naked eye, now at night could hardly
penetrate it.... A precaution, for they will be searching for us
perhaps.... Ah!..."

A white search-ray sprang from a house at the top of a hill nearby. It
leaped across the dark countryside, swept the water--which at that point
had broadened into a lagoon--and landed upon the boat. It was a light
strong enough to penetrate the barrage--the boat was disclosed to
observers in the house. But Tarrano raised a small metal projector. A
dull-red beam sprang from it and mingled with the other. A surge of
sparks; then Tarrano's red beam conquered. It absorbed the white light.
And Tarrano's beam was curved. It lay over the lake in a huge bow,
bending far out to one side. Yet its other end fell upon the hostile
house. The white search-ray from the house was submerged, bent outward
with Tarrano's beam. From the house, the observer could only gaze along
this curved light. He saw the image of the boat--not where the boat
really was--but as though the ray were straight.

Elza, staring with her heart in her throat, saw a ball of yellow fire
mount from the house. It swung into the air in