Tales from the vulgar unicorn- Thieves World 02 by Robert Asprin

end.'
    'I said that I only observed people entering on the north end. But I also observed something very interesting near here. I want to check it out. It may be nothing for us, but again...'
    Still moving slowly but faster than on the earth, they came to a little pool. It was about ten feet in diameter, a dark sheet of water on which bubbles appeared and popped. Smhee crouched down and stared at its sinister-looking surface. She started to whisper a question, but he said, 'Shh!'
    Presently, something scuttled with a clatter across the solid rock from the shore. She jumped but uttered no exclamation. The thing looked like a spider in the dark, an enormous one, larger than the one they'd killed. It paid no attention to them or perhaps it wasn't at all aware of them. It leaped into the pool and disappeared. Smhee said, 'Let's get behind that boulder.'
    When they were in back of it, she said, 'What's going on?'
    'When I was spying, I saw some things going into and coming out of this hole. It was too far away to see what they were, though I suspected they were giant spiders or perhaps crabs.'
    'So?'
    His hand gripped her wrist.
    'Wait!'
    The minutes oozed by like snails. Mosquitoes hummed around them, birds across the river called, and once she heard, or thought she heard, that peculiar half grunt, half-squall. And once she started when something splashed in the river. A fish. She hoped that was all it was.
    Smhee said softly, 'Ah!'
    He pointed at the pool. She strained her eyes and then saw what looked like a swelling of the water in its centre. The mound moved towards the edge of the pool, and then it left the water. It clacked as it shot towards the river. Soon another thing came and then another, and all of a sudden at least twenty popped up and clattered across the rocks.
    Smhee finally relieved her bursting question.
    'They look like the bengil crab of Sharranpip. They live in that hole but they must catch fish in the river.'
    'What is that to us?'
    'I think the pool must be an entrance to a cave. Or caves. The crabs are not water-breathers.'
    'Are they dangerous?'
    'Only when in water. On land they'll either run or, if cornered, try to defend themselves. They aren't poisonous, but their claws are very powerful.'
    He was silent for a moment, then said, 'The mage is using them to defend the entrance to a cave, I'm sure. An entrance which is also an exit. For him as well as for the crabs. That pool has to be one of his secret escape routes.'
    Masha thought, 'Oh, no!' and she rolled her eyes. Was this fat fool really thinking about trying to get inside through the pool? SL. 'How could the mage get out this way if the crabs would attack Bum?'
    'He would throw poisoned meat to them. He could do any number of things. What matters just now is that he wouldn't have bothered to bring their eggs along from Sharranpip unless he had a use for them. Nor would he have planted them here unless he needed them to guard this pool. Their flesh is poisonous to all living things except the ghoondah fish.'
    He chuckled. 'But the mage has outsmarted himself. If I hadn't noticed the bengil, I would never have considered that pool as an entrance.'
    While he had been whispering, another group had emerged and run for the river. He counted them, thirty in all.
    'Now is the time to go in,' he said. 'They'll all be feeding. That crab you first saw was their scout. It found a good place for catching fish, determined that there wasn't any enemy around, and returned with the good news. In some ways, they're more ant than crab. Fortunately, their nests aren't as heavily populated as an anthole.'
    He said, however, that they should wait a few minutes to make sure that all had left. 'By all, I mean all but a few. There are always a few who stay behind to guard the eggs.'
    'Smhee, we'll drown!'
    'If other people can get out through the pool, then we can get in.'
    'You don't know for sure that the pool is an escape route!'
    'What if the mage put the crabs there