The twins each slept in his own small tent. The tents were separated by ten long paces. If any kind of natural disaster struck, the separation might mitigate any loss.
Each awoke as the rain began, already alert when the ferocity of the storm struck them like a thrown anvil. Before the wind could whip their tents away and drench their belongings, they had taken down the poles and the tents became tarps that sheltered their possessions. As the wind's fury increased the twins lay upon the tents to keep them from being blown away. They were drenched, but that was merely temporarily unpleasant. They would dry more quickly and easily than the supplies they sheltered.
As a general rule Riotori do not wear sleep clothes. The naked young men lay on their stomachs, spread-eagled upon the collapsed tents, protecting their supplies. The wind and rain hammered them while the lightning illuminated the sky with angry bursts of jagged white and the thunder answered with ear-shattering blasts.
Feldspar and Gypsum ignored it all. This was not their first storm. A sudden river rushed upon them. Not by accident, they had pitched their tents on both sides of a slight depression and the muddy torrent charged between them. They had not expected the storm. Preparations like that were routine every time they made camp.
With grumbling patience they took all that the desert storm could crash upon them. They even dozed a little once it was clear no rushing water would threaten them.
The rain abated after an hour and the flash flooding diminished soon after. The clouds dispersed, revealing smug starlight and an observant half-moon.
The twins stood and shook themselves, water flying off their fur. With a cautious look at the sky and a quick conference they re-erected the poles in the tents and crawled back in. They would sleep until the sun awoke them. They had passed another test. Their father's advice that circumstances they did not expect were the ones they must prepare for was an intrinsic part of their awareness.
That would serve them again and again in their adventure.