with them also.

"Is the man from 1935 with Tugh and the Princess?" I asked.

"I think so. There are unfamiliar vibrations--perhaps those of the man
from the past."

The Robot was running the filaments of its fingers lightly over the
wall.

"I have it. The Princess pressed this switch."

The door opened; the narrow descending tunnel was wholly black.

"Where does this go, Migul?"

"I do not know."

The Robot was stooping to the floor. "It is a plain trail," it said.
"Come."[2]

[Footnote 2: Had Migul at that juncture traced Tina's movements--her
hand where it went along the tunnel-wall--we would have found the
light switch. But it chanced that the Robot's fingers went at once to
the ground and caught the foot-trail of Tugh.]

The remainder of that journey through the labyrinth of passages was
made in blank darkness, with only the faint lurid red beams from
Migul's eye-sockets to light our way. But we went swiftly, and without
incident. At last we went under the dam, up the spiral stairs and upon
the catwalk above the abyss, where the great spillway of falling water
arched out over us.

"The Power House," said Migul, "is where they went."

* * * * *

The Robot was obviously frightened, now. We were wet with spray. "I
should not be here," it said. "If the water gets into me--even though
I am well insulated--I will be destroyed!"

I recall as I write this how in Patton Place of 1935, one of the first
attacking Robots had exploded under a jet of water from the street
hydrant.

"I will stay behind you," Migul added. "They have a deranging ray in
the Power House, and they might use it on me. Will you protect me?"

"Yes, of course," I said.

I was ready to promise anything, if only I could get to Larry and
Tina, then back with them to Mary into the Time-cage; and if we were
safely out of this era, most assuredly I wanted none of it again.
Migul, as I advanced along the catwalk, followed behind me.

"You will kill Tugh?" it reiterated like an anxious child.

"Yes."

I saw that the catwalk terminated ahead under the Power House, where
steps led upward. Then I heard a cry:

"Help! Help! Here, inside the dam! Help!"

I stood transfixed, with horror tingling my flesh. The voice came
faintly from near at hand; it was muffled, and in the roar of the
falling water and lashing spray I barely heard it.

Then it came again. "Help us! Help us, quickly!"

It was an agonized,