Alrighty! Wentar is willing to blackmail the Trikistani to get the info out of Marl.
Wentar feels guilty about Altar's disappearance, he was the one who requested the additional help that lead to Altar's involvement. He also wishes to see the slaves returned, to make up for protecting the man who sent them into slavery. Wentar is on this mission more out of guilt then anything else at this point.
Blackmail seems to be their only lead into finding Altar and the Slaves, it is something he must do. There is no one else who can help them. So Wentar will bite the bullet and do what he has to, if only because no one else will. But he is still uneasy about this, it almost feels like a selfish act to ease his guilt and he knows that is could be a slippery slope into falling to the Dark Side if he doesn't tread carefully from this point on.
More or less, Wentar will use the blackmail, because they are out of ideas and someone has to help these slaves. Wentar will be the one to do it, he will take on the additional guilt to see this mission to it's end.
If our actions are revealed Wentar will take full responsibility for it. He will claim he made the arrangement alone and that Vlad and Emso didn't find out until after wards.
That being said Wentar will go contact the Grand Vizier of Triskatan from the Free Flier. Vlad and Emso can oversee the slave transfer.
"Greetings Grand Vizier," Wentar says, his stomach feeling knotted. "I'd like to ask you a favor.
"We've managed to track down a possible lead into finding Altar Vynn and the missing slaves. The problem is to get this information we have to cut a deal with the recently arrested Marl Ademiro. I was hoping you could use your position to help shorten his sentence and allow us to learn his information."
Wentar will try a reasonable approach at first.