The Old Map

Jad came running in his pyjamas, his green hat lopsided and his glasses in his hand. Saif came scuttling across the ceiling, then down the wall, and stood on his six legs on Reem's desk.

Reem showed them the rock, and the tiny drop on her finger.

Saif brought his blue eyes close, fired his scanning beam and made a long thinking noise. Then he said, "Analysis confirmed. Water ice. Ninety-seven per cent pure. What is hidden is often greater than what is seen."

"Where did this rock come from?" asked Jad, putting his glasses on in a hurry.

"From the edge of the canyon, near the black rocks to the north," said Reem. "I found it by a little opening in the ground, like a cave. But I didn't go in. Mum won't let me go near the edge."

"If there's ice in the rock..." said Jad slowly, his eyes shining behind his glasses, "then maybe there's more ice. Inside. Underground."

Reem looked at him. It was the first time she had ever seen Jad excited about anything on Mars.

Then Saif said something neither of them expected: