It was Lily who heard the noise first. 'What was that?' she asked.
'What was what?' asked Stafford.
'I don't know. It sounded like… tapping.'
They listened together. Now Gaille heard it too. Every four seconds or so. A gentle tap coming from somewhere high above. 'Hello!' called out Lily. 'Anyone up there?' She fell silent, the echoes died away. There it was again, its rhythm unchanged.
'Something's dripping,' said Lily.
'Yes,' said Stafford.
'Listen,' swallowed Gaille. 'I don't want to alarm you guys or anything, but if that is dripping, then maybe it's started raining.'
'But this is desert,' said Lily.
'It still rains here,' said Gaille. 'In fact, I was here during a storm once, years ago. You wouldn't believe how fierce they can get. And there's a rift in the plateau directly above us, remember? If there's some way for the water to get in…'
'It'll all end up draining down here,' muttered Stafford bleakly, finishing the thought for her.
'But it's only drips,' said Lily.
'So far,' agreed Gaille. But right then a second drip joined the first, at a slightly different tempo. And then, a minute after that, they heard the first trickle.