I squirmed shamefacedly. My ingratitude and callousness must be apparent to everyone; even Barbara, I remembered, had once asked me much the same questions Catty asked now. How could I explain, even to my own satisfaction, how procrastination and guilt made it impossible for me to take the simple steps to discover what had happened to my friend? By a tremendous effort I might have broken through the inertia years ago, just after Enfandin had been wounded, but each day and month between confirmed the impossibility more strongly. “Let the past take care of itself,” I muttered. “Oh Hodge! What a thing for an historian to say.” “Catty, I can’t.” The conversation made me nervous and fidgetty. It also made me remember much I preferred to let fade: the Grand Army, Sprovis, the counterfeit pesetas.... All the evil I had unwillingly abetted. If a man did nothing, literally nothing, all his life, then he might be free of culpability. Manichaeism, said Enfandin. No absolution. My idleness, I knew very well, heightened all these feelings of degradation. Were I able to continue in the happy, cocksure way I had gone about my note-gathering and the writing of volume one, I would have neither the time nor susceptibility to be plagued by this disquiet. As it was I seemed to be able to do nothing but act as audience for what was going on in the workshop. With childish eagerness Barbara and Ace explored HX-1’s possibilities for the next two months. They quickly learned that its range was limited to little more than a century, though this limit was subject to slight variations. When they tried to operate beyond this range the translation simply didnt take place, though the same feeling of dissolution occurred. When the light faded they were still in the present. Midbin’s venture into the hayfield had been a freak, possibly due to peculiar weather conditions at both ends of the journey. They set 1850 as a safe limit, with an undefined marginal zone further back which was not to be hazarded lest conditions change during the journey and the traveler be lost. Why this limit existed at all was a matter of dispute between them, a dispute of which I must admit I understood little. Barbara spoke of subjective factors which seemed to mean that HX-1 worked slightly differently in the case of each person it transported; Ace of magnetic fields and power relays, which didnt mean anything to me at all. The only thing they agreed on was that the barrier was not immutable; HX-2 or 3 or 20, if they were ever built, would undoubtedly overcome it. Nor would HX-1 work in reverse; the future remained closed, probably for similar reasons, whatever they were. Here again they disputed, Ace holding an HX could be built for this purpose, Barbara insisting that new equations would have to be worked out.