"I told you it's nebulous yet, with a lot of essential details yet to be filled in--" Seaton paused, then went on, doubtfully: "It's pretty wild--I don't know whether--" "Now you _must_ tell us about it, Dick," Margaret urged. "I'll say you've got to," Dorothy agreed. "You've had a lot of ideas wild enough to make any sane creature's head spin around in circles before this, but not one of them was so hair raising that you were backward in talking about it. This one must be the prize brain storm of the universe--spill it to us!" "All right, but remember that it's only half baked and that you asked for it. I'm doping out a way of sending them back to their own Solar System, planet and all." "What!" exclaimed Margaret. Dorothy simply whistled--a long, low whistle highly eloquent of incredulity. "Maintenance of temperature? Time? Power? Control?" Crane, the imperturbable, picked out unerringly the four key factors of the stupendous feat. "Your first three objections can be taken care of easily enough," Seaton replied positively. "No loss of temperature is possible through a zone of force--our own discovery. We can stop time with a stasis--we learned that from watching those four-dimensional folks work. The power of cosmic radiation is practically infinite and eternal--we learned how to use that from the pure intellectuals. Control is the sticker, since it calls for computations and calculations at present impossible; but I believe that when we get our mechanical brain done, it will be able to work out even such a problem as that." "What d'you mean, mechanical brain?" demanded Dorothy. "The thing that is going to run our sixth-order projector," Seaton explained. "You see, it'll be altogether too big and too complicated to be controlled manually, and thought--human thought, at least--is on one band of the sixth order. Therefore the logical thing to do is to build an artificial brain capable of thinking on _all_ bands of the order instead of only one, to handle the whole projector. See?" "No," declared Dorothy promptly, "but maybe I will, though, when I see it work. What's next on the program?" "Well, it's going to be quite a job to build that brain and we'd better be getting at it, since without it there'll be no _Skylark Four_--" "Dick, I object!" Dorothy protested vigorously. "_The Skylark of Space_ was a nice name--" "Sure, you'd think so, since you named her yourself," interrupted Seaton in turn, with his disarming grin.