ndolph, "till we know what's up."

Allenby made an interrogative sound at the chief. The chief squeaked and
pointed at the ground. We looked. He was pointing at his shadow.

Randolph stirred uncomfortably.

"Hold still," Allenby warned him, and again he made the questioning
sound.

The chief pointed up the street. Then he pointed down the street. He
bent to touch his shadow, thumping it with thin fingers. Then he pointed
at the wall of a house nearby.

We all looked.

Straight lines had been painted on the curved brick-colored wall, up and
down and across, to form many small squares about four inches across. In
each square was a bit of squiggly writing, in blackish paint, and a
small wooden peg jutting out from the wall.

Burton said, "Looks like a damn crossword puzzle."

"Look," said Janus. "In the lower right corner--a metal ring hanging
from one of the pegs."

* * * * *

And that was all we saw on the wall. Hundreds of squares with figures in
them--a small peg set in each--and a ring hanging on one of the pegs.

"You know what?" Allenby said slowly. "I think it's a calendar! Just a
second--thirty squares wide by twenty-two high--that's six hundred and
sixty. And that bottom line has twenty-six--twenty-_seven_ squares. Six
hundred and eighty-seven squares in all. That's how many days there are
in the Martian year!"

He looked thoughtfully at the metal ring. "I'll bet that ring is hanging
from the peg in the square that represents _today_. They must move it
along every day, to keep track...."

"What's a calendar got to do with my crossing the street?" Randolph
asked in a pained tone.

He started to take another step. The chief squeaked as if it were a
matter of desperate concern that he make us understand. Randolph stopped
again and swore impatiently.

Allenby made his questioning sound again.

The chief pointed emphatically at his shadow, then at the communal
calendar--and we could see now that he was pointing at the metal ring.

Burton said slowly, "I think he's trying to tell us that this is
_today_. And such-and-such a _time_ of day. I bet he's using his shadow
as a sundial."

"Perhaps," Allenby granted.

Randolph said, "If this monkey doesn't let me go in another minute--"

The chief squeaked, eyes concerned.

"Stand still," Allenby ordered. "He's trying to warn you of some
danger."

The chief pointed down the street again and, instead of squealing,
rev