You stand alone in a vast desert. On the horizon, you see a far-distant range of mountains. Their peaks shimmer and dance.

A few metres before you is the edge of a salt pan that stretches towards the mountains, its far edge smearing into the furnace air.

You turn around.

In the other direction, not far away, is a rock outcrop.

Three storeys tall, it appears to be made of pale limestone, its edges fluted and scoured by the winds.

At the base of this outcrop is an opening. You cannot see what lies beyond it.

Will you enter the opening, set off towards the mountains or languish at the threshold, tormented by indecision?