“And your own constables on Phobos?”

“Same thing,” said the policeman grimly. “I’ve slapped on an embargo—nobody but me has left this settlement since the loss was discovered. I’ve had every room and tunnel and warehouse searched.” He tried to scratch his head, a frustrating attempt when one is in a spacesuit. “I can’t maintain those restrictions much longer. Ships are coming in and the consignees want their freight.”

“Hnachla. That puts us under a time limit, then.” Syaloch nodded to himself. “Do you know, this is a fascinating variation of the old locked room problem. A robot ship in transit is a locked room in the most classic sense.” He drifted off into a reverie.

Gregg stared bleakly across the savage horizon, naked rock tumbling away under his feet, and then back over the field. Odd how tricky your vision became in airlessness, even when you had bright lights. That fellow crossing the field there, under the full glare of sun and floodlamps, was merely a stipple of shadow and luminance…what the devil was he doing, tying a shoe of all things? No, he was walking quite normally—

“I’d like to put everyone on Phobos under scop,” said Gregg with a violent note, “but the law won’t allow it unless the suspect volunteers—and only my own men have volunteered.”

“Quite rightly, my dear fellow,” said Syaloch. “One should at least have the privilege of privacy in his own skull. And it would make the investigation unbearably crude.”

“I don’t give a fertilizing damn how crude it is,” snapped Gregg. “I just want that box with the crown jewels safe inside.”

“Tut-tut! Impatience has been the ruin of many a promising young police officer, as I seem to recall my spiritual ancestor of Earth pointing out to a Scotland Yard man who—hm—may even have been a physical ancestor of yours, Gregg. It seems we must try another approach. Are there any people on Phobos who might have known the jewels were aboard this ship?”

“Yes. Two men only. I’ve pretty well established that they never broke security and told anyone else till the secret was out.”

“And who are they?”

“Technicians, Hollyday and Steinmann. They were working at Earth Station when the Jane was loaded. They quit soon after—not at the same time—and came here by liner and got jobs. You can bet that their quarters have been searched!”

“Perhaps,” murmured Syaloch, “it would be worthwhile to interview the gentlemen in question.”

* * *

Steinmann, a thin redhead, wore truculence like a mantle; Hollyday merely looked worried. It was no evidence of guilt—everyone had been rubbed raw of late. They sat in the police office, with Gregg behind the desk and Syaloch leaning against the wall, smoking and regarding them with unreadable yellow eyes.

“Damn it, I’ve told this over and over till I’m sick of it!” Steinmann knotted his fists and gave the Martian a bloodshot stare. “I never touched the things and I don’t know who did. Hasn’t any man a right to change jobs?”