Not knowing how we had entered the valley, I was equally uncertain how to get out of it. I tried to reassure myself. The sun had disappeared behind the cliffs to our right, so we had to be traveling south. We were following the direction of the stream, which meant we were probably headed seaward. South and seaward, just as the tavernkeeper had advised. But where in Hades were we? Where was Massilia, with Caesar's army camped before it? And how could we exit this hall of stone?

A band of lurid sunlight lit up the highest reaches of the eastern cliffs to our left, turning the chalk-white stone blood-red. The glare was blinding. When I lowered my eyes, the deepening shadows around us seemed even darker. The bubbling water in the stream looked black.

A warm breeze sighed through the valley. Sounds and sights became deceptive uncertain; in the stirring of the leaves I heard men moaning, snakes hissing. Strange phantoms appeared among the rocks-twisted faces, tormented bodies, impossible freaks-then as suddenly vanished back into the stone. Despite the warm breeze, I shivered.

Riding behind me, Davus whistled a tune that a wandering Gaulish singer had performed at the tavern the previous night. Not for the first time in the twenty-odd days since we left Rome, I wondered if my imperturbable son-in-law was truly fearless, or if he simply lacked imagination.

Suddenly I gave a start. I must have pulled on the reins and expelled a noise of alarm, for my horse stopped short and Davus drew his short sword. "Father-in-law, what is it?"

I blinked. "Nothing…"

"But, father-in-law-"