The greatest treasure that washed ashore wasn't the gold. Fleeting moonlight revealed the ghostly outline of a pirate flagship riding distant waves. Then all was dark again under scurrying clouds before a mermaid rose from the sea, shimmering under a moonbeam. The man who called himself Castaway stood spellbound as she promised treasure and a message to the master of the island. But the treasure she offered was lashed to small powder kegs that formed a makeshift raft. Coul