Bosco, the Vice Admiral of Spain (meaning he's a Big Deal in the Spanish navy) has just arrived on his ship, the Flying Dragon, which sounds pretty fierce as far as ships go. (But not as boss as this one.)
Bosco's meeting with Ferneze and the Knights of Malta because he wants to sell the Greek, Turkish, and African slaves he's captured. At least he's not discriminating?
Problem is, Ferneze explains, the Turks only just agreed to not invade Malta and are probably really not cool with the idea of the Maltese selling Turkish slaves.
Bosco doesn't get it—the Maltese are Christians, right? So why are they in cahoots with the Muslim Turks?
Ferneze explains the treaty Malta's made with the Turks, and the money he's raised to pay them off.
Bosco tells him to keep the money. Spain will fight off the Turks if Malta becomes part of Spain and lets the Spanish sell slaves there.
This sounds like a great deal to Ferneze, who likes the idea of killing the Turks a lot more than giving them money.