Foster leaned over, read the fine print.
"Stonehenge."
I read from the encyclopedia page:
—this great stone structure, lying on the Plain of Salisbury, Wiltshire, England, is pre-eminent among megalithic monuments of the ancient world. Within a circular ditch 300' in diameter, stones up to 22' in height are arranged in concentric circles. The central altar stone, over 16' long, is approached from the northeast by a broad roadway called the Avenue—
"It is not an altar," said Foster.
"How do you know?"
"Because——" Foster frowned. "I know, that's all."
"The journal said the stones were arranged in the sign of the Two Worlds," I said. "That means the concentric circles, I suppose; the same thing that's stamped on the cover of the notebook."
"And the ring," Foster said.