Who can I ask? he asked himself, that would know, offhand, if Plowman's Planet is Sirius five? Kate. Kate would know.

But, he thought as he started to dial her office number, if I'm going to emigrate to Plowman's Planet I don't want her to know; she'll be able to trace me re my back alimony payments.

Once more he picked up the unsigned note, studied it. And, in a gradual, seeping fashion, a realization concerning it suffused his mind and entered into his field of awareness. There were more words on the note in some kind of semiinvisible ink. Runic writing? he wondered; he felt a sort of wicked, animal excitement, as if he had found a carefully protected trail.

He dialed Smith's number. "If you got a letter," Joe said, "with semi-invisible runic writing on it, how would you—you in particular—go about making it visible?"

"I'd hold it over a heat source," Smith said.

"Why?" Joe said.

"Because it's most likely written in milk. And writing in milk turns black over a heat source."

"Runic writing in milk?" Joe said angrily.

"Statistics show—"

"I can't imagine it. I simply can't imagine it. Runic writing in milk." He shook his head. "Anyway, what statistics are there on runic writing? This is absurd." He got out his cigarette lighter and held it beneath the sheet of paper. At once, black letters became visible.

WE SHALL RAISE HELDSCALLA.

"What's it say?" Smith asked.

Joe said, "Listen, Smith; you haven't used the encyclopedia in the last twenty-four hours, have you?"

"No," Smith said.

Joe said, "Call it. Ask it if Plowman's Planet is another name for Sirius five. And ask it what ‘Heldscalla' consists of." I guess I could ask the dictionary that, he said to himself.