physicist frank elby was a few years older than barney, an acquaintance since their university days. elby was ambitious, capable, slightly dishonest; on occasion he provided barney with contraband information for which he was generously paid.

over lunch barney broached a business matter which would be financially rewarding to both of them, and should not burden elby's conscience unduly. elby reflected, and agreed. the talk became more general. presently barney remarked, "ran into an old acquaintance of ours the other day. remember dr. mcallen?"

"oliver b. mcallen? naturally. haven't heard about him in years. what's he doing?"

barney said he had only seen the old man, hadn't spoken to him. but he was sure it was mcallen.

"where was this?" elby asked.

"sweetwater beach. small town down the coast."

elby nodded. "it must have been mcallen. that's where he had his home."

"he was looking hale and hearty. they didn't actually institutionalize him at the time of his retirement, did they?"

"oh, no. no reason for it. except on the one subject of that cockeyed invention of his, he behaved perfectly normally. besides he would have hired a lawyer and fought any such move. he had plenty of money. and nobody wanted publicity. mcallen was a pretty likable old boy."

"the university never considered taking him back?"

elby laughed. "well, hardly! after all, man—a matter transmitter!"

barney felt an almost electric thrill of pleasure. right on the nose, brother chard! right on the nose.

he smiled. "was that what it was supposed to be? i never was told all the details."

elby said that for the few who were informed of the details it had been a seven-day circus. mcallen's reputation was such that more people, particularly on his staff, had been ready to believe him that were ready to admit it later. "when he'd left—you know, he never even bothered to take that 'transmitter' along—the thing was taken apart and checked over as carefully as if somebody thought it might still suddenly start working. but it was an absolute goldberg, of course. the old man had simply gone off his rocker."

"hadn't there been any indication of it before?"

"not that i know of. except that he'd been dropping hints about his gadget for several months before he showed it to anyone," elby said indifferently. the talk turned to other things.

the rest was routine, not difficult to carry out. a small cottage on mallorca, near the waterfront, was found to be in mcallen's name. mcallen's liquid assets were established to have dwindled to something less than those of john emanuel fredericks, who patronized the same local bank as his employer. there had been frequent withdrawals of large, irregular sums throughout the past years. the withdrawals were not explained by mcallen's frugal personal habits; even his fishing excursions showed an obvious concern for expense. the retention of the mediterranean retreat, modest though it was, must have a reason beyond simple self-indulgence.

barney arranged for the rental of a bungalow in the outskirts of sweetwater beach, which lay uphill from the old house in which mcallen and fredericks lived, and provided a good view of the residence and its street entry. he didn't go near the place himself. operatives of a los angeles detective agency went on constant watch in the bungalow, with orders to photograph the two old men in the other house and any visitors at every appearance, and to record the exact times the pictures were taken. at the end of each day the photographs were delivered to an address from where they promptly reached barney's hands.

a european agency was independently covering the mallorca cottage in the same manner.

nearly four weeks passed before barney obtained the exact results he wanted. he called off the watch at both points, and next day came up the walk to mcallen's home and rang the doorbell. john fredericks appeared, studied barney's card and barney with an air of mild disapproval, and informed him that dr. mcallen did not receive visitors.

"so i've been told," barney acknowledged pleasantly. "please be so good as to give the doctor this."

fredericks' white eyebrows lifted by the barest trifle as he looked at the sealed envelope barney was holding out. after a moment's hesitation he took it, instructed barney to wait, and closed the door firmly.

listening to fredericks' footsteps receding into the house, barney lit a cigarette, and was pleased to find that his hands were as steady as if he had been on the most ordinary of calls. the envelope contained two sets of photographs, dated and indicating the time of day. the date was the same for both sets; the recorded time showed the pictures had been taken within fifteen minutes of one another. the central subject in each case was dr. mcallen, sometimes accompanied by fredericks. one set of photographs had been obtained on mallorca, the other in sweetwater beach at mcallen's house.

barring rocket assists, the two old men had been documented as the fastest moving human beings in all history.

several minutes passed before fredericks reappeared. with a face which was now completely without expression, he invited barney to enter, and conducted him to mcallen's study. the scientist had the photographs spread out on a desk before him. he gestured at them.

"just what—if anything—is this supposed to mean, sir?" he demanded in an unsteady voice.

barney hesitated aware that fredericks had remained in the hall just beyond the study. but fredericks obviously was in mcallen's confidence. his eavesdropping could do no harm.

"it means this, doctor—" barney began, amiably enough; and he proceeded to tell mcallen precisely what the photographs meant. mcallen broke in protestingly two or three times, then let barney conclude his account of the steps he had taken to verify his farfetched hunch on the pier without further comment. after a few minutes barney heard fredericks' steps moving away, and then a door closing softly somewhere, and he shifted his position a trifle so that his right side was now toward the hall door. the little revolver was in the right-hand coat pocket. even then barney had no real concern that mcallen or fredericks would attempt to resort to violence, but when people are acutely disturbed—and mcallen at least was—almost anything can happen.