Excerpt:

Antonio was the last to arrive at the Borgia's dinner party and the first to be poisoned.   He collapsed into the chair next to mine and launched into a litany of complaints.

"Raffael!  The infernal carriage broke down three times en route.  I shall have to buy another."

I made sympathetic noises, despite the fact that I'd walked to the party.  I was a fourth son, while he was the first and only.  He was my oldest friend, and yet--

It will be a pleasure to kill him.