Blue and Gold — K.J. Parker

'Well, let me see,' I said, as the innkeeper poured me a beer. 'In the morning I discovered the secret of changing base metal into gold. In the afternoon, I murdered my wife.'

For a man as remarkable as the philosopher Saloninus, just another day.

Of course, we only have his word for it, and Saloninus has been known to be creative with the truth. Little white lies are inevitable expedients when you're one jump ahead of the secret police and on the brink of one of the greatest discoveries in the history of alchemy. But why would a scientist with the world's most generous, forgiving patron be so desperate to run away? And what, if anything, has blue got to do with gold?