Not if he can cross into Dimension X by the power of his mind alone.

For the first time he wouldn't reach Dimension X alone.

But living long enough in Dimension X was sometimes a problem.

Dimension X could not be explored or exploited without somebody going through the computer.

Dimension X was discovered quite by accident, like so much else in the history of science.

Dimension X could never be explored or exploited this way.

Dimension X is a completely unpredictable environment, so it's hard to say what's an unnecessary risk.

How many times could he go into Dimension X and come back?

That boy has been into Dimension X four times and tomorrow he goes out again.

"When did you return from your last trip into Dimension X, my boy?"