ity of discontinuing his investigations. You can do it, and you
alone, now that you fully understand."

"Sa-ay! You're putting it up to me entirely?"

"Nearly so, and there is no alternative. I believe I have not
misjudged you; you will not fail, of that I am certain. For the sake
of your own kind, for the love of Joan Parker--you will not fail. And
for me--for this small measure of atonement it is permitted that I
make or help to make possible--"

"No, I'll not fail. Take me to them, quick." Bert grinned
understandingly as the Wanderer straightened his broad shoulders and
extended his hand.

There was no lack of substantiality in the mighty grip of those
closing fingers.

* * * * *

Again the sphere's invisible motors increased speed, and again the
dizzying kaleidoscope of color swept past them more furiously.

"We will now overtake them--your friends," said the Wanderer, "in the
very act of passing between planes."

"Overtake them...." Bert mumbled. "I don't get it at all, this time
traveling. It's over my head a mile."

"It isn't time travel really," explained the Wanderer. "We are merely
closing up the time-space interval, moving to the precise spot in the
universe where your friend's laboratory existed at the moment of
contact between planes with your world and that of the Bardeks. We
shall reach there a few seconds after the actual capture."

"No chance of missing?" Bert watched the Wanderer as he consulted his
mathematical data and made new adjustments of the controls.

"Not the slightest; it is calculated to a nicety. We could, if we
wished, stop just short of the exact time and would see the
re-occurrence of their capture. But only as unseen observers--you can
not enter the plane as a material being during your own actual past,
for your entity would then be duplicated. Of course, I can not enter
in any case. But, moving on to the instant after the event, as we
shall do, you may enter either plane as a material being or move
between the two planes at will by means of the gateway provided by Tom
Parker's force area. Do you not now understand the manner in which you
will be enabled to carry out the required procedure?"

"H-hmm!" Bert wasn't sure at all. "But this moving through time," he
asked helplessly, "and the change from one plane of oscillation to
another--they're all mixed up--what have they to do with each other?"

"All five dimensions of our universe are defi