"Sure," answered Benny. "According to the mechanical mind here, they've been on Mojave for twenty minutes." "Thanks." To Arden he said: "Something's strictly fishy." Arden sat at the machine and pounded the keys: _SOLAR QUEEN_ DUE TO ARRIVE AT 19:06:41. IT IS NOW 19:27:00. BEAM CONTROL SAYS TRANSMISSIONS ENDED BECAUSE OF COINCIDENCE BETWEEN TERRA BEAM AND STATION-TO-SHIP BEAM. PLEASE CHECK. Arden fretted and Walt stamped up and down the room during the long minutes necessary for the message to reach Terra and the answer to return. It came right on the tick of the clock: HAVE CHECKED COURSE CONSTANTS. _SOLAR QUEEN_ OVER-DUE NOW FIFTY MINUTES. OBVIOUSLY SOMETHING WRONG. CAN YOU HELP? Walt smiled in a grim fashion. "Help!" he said. "We go on and on for years and years with no trouble--and now we've lost the third ship in a row." "They claim that those things always run in threes," said Arden. "What are we going to do?" "I don't know. We'll have to do something. Funny, but the one reason we must do something is the same reason why something can be done." "I don't get that." "With Channing on the _Solar Queen_, something can be done. I don't know what, but I'll bet you a new hat that Don will make it possible for us to detect the ship. There is not a doubt in my mind that if the ship is still spaceworthy, we can narrow the possibilities down to a thin cone of space." "How?" "Well," said Franks, taking the fountain pen out of the holder on the desk and beginning to sketch on the blotter, "the course of the _Solar Queen_ is not a very crooked one, as courses go. It's a very shallow skew curve. Admitting the worst, collision, we can assume only one thing. If the meteor were small enough to leave the ship in a floating but undirigible condition, it would also be small enough to do nothing to the general direction of the ship. Anything else would make it useless to hunt, follow?" "Yes, go on." "Therefore we may assume that the present position of the _Solar Queen_ is within the volume of a cone made by the tangents of the outermost elements of the space curve that is the _Solar Queen's_ course. We can take an eight-thousand-mile cylinder out of one place--for the origin of their trouble is between Mars and Terra and the 'shadow' of Terra in the cone will not contain the _Solar Queen_." "Might have passed close enough to Terra to throw her right into the 'shadow' of Terra by attraction," objected Arden. "Yeah, you're right. O.K., so we can't take out that cylinder of space. And we add a sort of side-wise cone on to our original cone, a volume through which the _Queen_ might have flown after passing close enough to Terra to be deflected. I'll have the slipstick experts give a guess as to the probability of the _Queen's_ course, and at the same time we'll suspend all incoming operations. I'm going to set up every kind of detector I can think of, and I don't want anything upsetting them."