have a look."

Brad went over and stood by the thing. He examined it, as Turran had done, and found nothing to press or pull.

"Beats me," he said at last "Never seen anything like it before."

'Try kicking it?"

"What good would that do?"

"Go on Dad."

Brad gave the pipe a hefty boot. The pipe sounded like solid metal, so it wasn't a hollow pipe, but nothing else happened. He turned to go.

"Maybe it's something to do with a survey?"

"Probably," said Brad "Some scientists might have set it up to measure something. The weather perhaps? Ozone? Desert temperatures? Who knows!

Maybe it fell from a weather balloon – should be a serial number or something . . . Come on, let's get out of this sun before we burn!"

Turran had a last look at the thing. He wondered if the top might unscrew, so he grabbed it and heaved. It turned.

"Dad!" he called, "1 think the top comes off!"

His father leaned forward look.

The top turned, all by itself, until it was sitting on a thread half its own length, then it buzzed quietly and began to hum. The outer shell, which Turran had turned, fell off, revealing a white metal, roughly the same shape as the shell – a bit like a caterpillar shedding its outer skin.

"Get back," ordered Brad cautiously, pulling Turran by the sleeve.

The top of the pipe began to unfold, like a flower, with metal wings, like petals, spread between delicate metal fingers, and a red light pulsed at its centre.

"What is it?!" said Turran.

"I don't know," said Brad, "Better keep clear of it for a while, till we know if its safe or not."

"Maybe its a bomb?"

"What would someone put a bomb way out here for?"