Costello advanced and shook hands with him. "How do you do, Mr. Harvey? It's good to see you again."
"It's good to see you. I'm mighty glad to see you folks alive and in one piece. I thought you had had it."
"Not quite. But it was a near thing."
Isobel said, "Don, you look older-much older. And how thin you are!"
He grinned at her. "You look just the same, Grandma."
Phipps interrupted, "Much as I dislike breaking up Old Home Week we have no time to waste. Miss Costello, we want the ring."
"The ring?"
"He means," explained Don, "the ring I left with you."
"Ring?" said Mr. Costello. "Mr. Harvey, did you give my daughter a ring?"
"Well, not exactly. You see..."
Phipps interrupted again. "It's the ring, Jim-the message ring. Harvey was the other courier-and it seems he made your daughter sort of a deputy courier."
"Eh? I must say I'm confused." He looked at his daughter.
"You have it?" Don asked her. "You didn't lose it?"
"Lose your ring? Of course not, Don. But I had thought-never mind; you want it back now." She glanced around at the eyes on her-fourteen, counting Sir Isaac's-then moved away and turned her back. She turned around again almost immediately and held out her hand. "Here it is."
Phipps reached for it. Isobel drew her hand away and handed it to Don. Phipps opened his mouth, closed it again, then reopened it. "Very well-now let's have it, Harvey."
Don put it in a pocket. "You never did get around to explaining why I should turn it over to you."
"But-" Phipps turned quite red. "This is preposterous) Had we known it was here, we would never have bothered to send for you-we would have had it without your leave."
"Oh, no!" '
Phipps swung his eyes to Isobel. "What's that, young lady? Why not?"
"Because I wouldn't have given it to you-not ever. Don told me that someone was trying to get it away from him. I didn't know that you were the one."
Phipps, already red-faced, got almost apoplectic. "I've had all this childish kidding around with serious matters that I can stand." He took two long strides to Don and grasped him by the arm. "Cut out the nonsense and give us that message!"
Don shook him off and backed away half a step, all in one smooth motion-and Phipps looked down to see the point of a blade almost touching his waistband. Don held the knife with the relaxed thumb-and-two-finger grip of those who understand steel.
Phipps seemed to have trouble believing what he saw. Don said to him softly, "Get away from me."
Phipps backed away. "Sir Isaacl"
"Yes," agreed Don. "Sir Isaac-do I have to put up with this in your house?"
The dragon's tentacles struck the keys, but only confused squawking came out. He stopped and started again and said very slowly, "Donald-this is your house. You are always safe in it. Please-by the service you did me--put away your weapon."
Don glanced at Phipps, straightened up and caused his knife to disappear. Phipps relaxed and turned to the dragon. "Well, Sir Isaac? What are you going to do about it?"
Sir Isaac did not bother with the voder. "Remove thyself!"
"Eh?"
"You have brought dissension into this house. Were you not both in my house and of my family? Yet you menaced him. Please go-before you cause more sorrow."
Phipps started to speak, thought better of it-left. Don said, "Sir Isaac, I am terribly sorry. I-
"Let the waters close over it. Let the mud bury it. Donald, my dear boy, how can I assure you that what we ask of you is what your honored parents would have you do, were they here to instruct you?"
Don considered this. "I think that's just the trouble, Sir Isaac-I'm not your `dear boy.' I'm not anybody's `dear boy.' My parents aren't here and I'm not sure that I would let them instruct me if they were. I'm a grown man now-I'm not as old as you are, not by several centuries. I'm not very old even by human standards-Mr. Phipps still classes me as a boy and that was what was wrong. But I'm not a boy and I've got to know what's going on and make up my own mind. So far, I've heard a lot of sales talk and I've been subjected to a lot of verbal pushing around. That won't do; I've got to know the real facts."
Before Sir Isaac could reply they were interrupted by another sound-Isobel was applauding. Don said to her. "How about you, Isobel? What do you know about all this?"
"Me? Nothing. I couldn't be more in the dark if I were stuffed in a sack. I was just cheering your sentiments."
"My daughter," Mr. Costello put in crisply, "knows nothing at all of these things. But I do-and it appears that you are entitled to answers."
"I could certainly use some!"
"By your leave, Sir Isaac?" The dragon ponderously inclined his head; Costello went on, "Fire away. I'll try to give you straight answers."
"Okay-what's the message in the ring?"
"Well, I can't answer that exactly or we wouldn't need the message ourselves. I know that it's a discussion of certain aspects of physics-gravitation and inertia and spin and things like that. Field theory. It's certainly very long and very complicated and I probably wouldn't understand it if I knew exactly what was in it. I'm simply a somewhat rusty communications engineer, not a topflight theoretical physicist."
Don looked puzzled. "I don't get it. Somebody tucks a physics book into a ring-and then we play cops-and-robbers all around the system. It sounds silly. Furthermore, it sounds impossible." He took the ring out and looked at it; the light shone through it clearly. It was just a notions counter trinket-how could a major work on physics be hidden in it?
Sir Isaac said, "Donald, my dear- I beg pardon. Shucks! You mistake simple appearance for simplicity. Be assured; it is in there. It is theoretically possible to have a matrix in which each individual molecule has a meaning-as they do in the memory cells of your brain. If we had such subtlety, we could wrap your Encyclopedia Britannica into the head of a pin-it would be the head of that pin. But this is nothing so difficult."
Don looked again at the ring and put it back in his pocket. "Okay, if you say so. But I still don't see what all the shooting is about."
Mr. Costello answered, "We don't either-not exactly. This message was intended to go to Mars, where they are prepared to make the best use of it. I myself had not even heard about the project except in the most general terms until I was brought here. But the main idea is this: the equations that are included in this message tell how space is put together-and how to manipulate it. I can't even imagine all the implications of that-but we do know a couple of things that we expect from it, first, how to make a force field that will stop anything, even a fusion bomb, and second, how to hook up a space drive that would make rocket travel look like walking. Don't ask me how-I'm out of my depth. Ask Sir Isaac."
"Ask me after I've studied the message," the dragon commented dryly.
Don made no comment. There was silence for some moments which Costello broke by saying, "Well? Do you want to ask anything? I do not know quite what you do know; I hardly know what to volunteer."
"Mr. Costello, when I talked to you in New London, did you know about this message?"
Costello shook his head. "I knew that our organization had great hopes from an investigation going on on Earth. I knew that it was intended to finish on Mars-you see, I was the key man, the `drop box,' for communication to and from Venus, because I was in a position to handle interplanetary messages. I did not know that you were a courier-and I certainly did not know that you had entrusted an organization message to my only daughter." He smiled wryly. "I might add that I did not even identify you in my mind as the son of two members of our organization, else there would have been no question about handling your traffic whether you could pay for it or not. There were means whereby I could spot organization messages-identifications that your message lacked. And Harvey is a fairly common name."