heory； there's no reason it couldn't be done。 Then just think： the entire planet would be free of its dependency on fossil fuels。 。。。 The whole history of mankind would be changed。〃
Barnes said； 〃Probably make a hell of a weapon； too。〃
〃Even a very tiny black hole would be a little too powerful to use as a weapon。〃
〃So you think this ship went out to capture a black hole？〃
〃I doubt it；〃 Ted said。 〃The ship is so strongly made； so shielded against radiation； that I suspect it was intended to go through a black hole。 And it did。〃
〃And that's why the ship went back in time？〃 Norman said。
〃I'm not sure；〃 Ted said。 〃You see； a black hole really is the edge of the universe。 What happens there isn't clear to anybody now alive。 But what some people think is that you don't go through the hole； you sort of skip into it； like a ＇＇134＇＇ pebble skipping over water； and you get bounced into a different time or space or universe。〃
〃So the ship got bounced？〃
〃Yes。 Possibly more than once。 And when it bounced back here； it undershot and arrived a few hundred years before it left。〃
〃And on one of its bounces； it picked up that？〃 Beth said； pointing to the monitor。
They looked。 The sphere was still closed。 But lying next to it； sprawled on the deck in an awkward pose； was Harry Adams。
For a moment they thought he was dead。 Then Harry lifted his head and moaned。
THE SUBJECT
Norman wrote in his notebook： Subject is a thirty…year…old black mathematician who has spent three hours inside a sphere of unknown origin。 On recovery from the sphere was stuporous and unresponsive； he did not know his name； where he was； or what year it was。 Brought back to habitat； slept for one half…hour then awoke abruptly pl