“But ... but—” “You can verify every fact, study every move, every actor. You can write history as no one ever did before, for youll be writing as a witness, yet with the perspective of a different period. Youll be taking the mind of the present, with its judgment and its knowledge of the patterns, back to receive the impressions of the past. It almost seems HX-1 was devised especially for this.” There was no doubt she believed, that she was really and unselfishly glad her work could aid mine. I was overcome by pity, helpless to soften the disillusionment so soon to come and filled with an irrational hatred of the thing she had built and which was about to destroy her. I was saved from having to mask my emotions by the arrival of her father, Ace, and Midbin. Thomas Haggerwells began tensely, “Barbara, Ace tells me you intend to try out this—this machine on yourself. I can’t believe you would be so foolhardy.” Midbin didnt wait for her to reply. I thought with something of a shock, Midbin has gotten old; I never noticed it. “Listen to me. There’s no point now in saying part of your mind realizes the impossibility of this demonstration and that it’s willing for you to annihilate yourself in the attempt and so escape from conflicts which have no resolution. Although it’s something you must be at least partly aware of. But consider objectively the danger involved in meddling with unknown natural laws—” Ace Dorn, who looked as strained as they in contrast to Barbara’s ease, growled, “Let’s go.” She smiled reassuringly at us. “Please, Father, don’t worry; there’s no danger. And Oliver....” Her smile was almost mischievous and very unlike the Barbara I had known. “Oliver, HX-1 owes more to you than you will ever know.” She ducked under the transparent ring and walked to the center of the floor, glancing up at the reflector, moving an inch or two to stand directly beneath it. “The controls are already adjusted to minus fifty-two years and a hundred and fifty-three days,” she informed us conversationally. “Purely arbitrary. One date is good as another, but January 1, 1900 is an almost automatic choice. I’ll be gone sixty seconds. Ready, Ace?” “Ready.” He had been slowly circling the engines, checking the dials. He took his place before the largest, the monster in the corner, holding a watch in his hand. “Three forty-three and ten,” he announced. Barbara was consulting her own watch. “Three forty-three and ten,” she confirmed. “Make it at three forty-three and twenty.” “OK. Good luck.” “You might at least try it on an animal first,” burst out Midbin, as Ace twirled the valve under his hand. The transparent ring glowed, the metal reflector threw back a dazzling light. I blinked. When I opened my eyes the light was gone and the center of the workshop was empty.