Barabas, though, knows he has a problem—he may be Governor, but it doesn't do him much good when everybody in Malta wants him dead.If he wants to stay alive, he's going to have to play nice with Ferneze and his peeps.
He sends the other prisoners and guards away, so it's just him and Ferneze.
To Ferneze's surprise, Barabas doesn't want to kill him—instead, he wants to make him a deal:
Barabas will kill Calymath and his men and free Malta in return for an enormous sum of money.
He's going to invite Calymath to a banquet, he says, where Ferneze will have to come and perform some undisclosed task.
In order to raise the money, Ferneze is set free to solicit his fellow Maltese—apparently "Bake Sale Fundraiser to Massacre Our Turkish Overseers" would have been too obvious.
Alone, Barabas again professes that he's loyal to nobody—he's batting for the Turks and the Maltese in turn, and whichever comes out on top is the party he'll align himself with.