Keep sportsin', guys!
No, seriously, have to keep this quick, since gamers are here fairly soon and I have to cook.
OK, so, last time they got in and got Imre with entirely too much ease, because I'm a fucking pushover and I should have pinned them down and left it as a cliffhanger or something. But for whatever reason I get frustrated when the only player with any tactical mentality gets hung up on how much trigger wax a P89-G Machine Finger-Blaster Killypump takes instead of using the incredibly simple game system pant pant pant anyway.
Gun bunnies, man.
So, with that in mind, let's assume that the dudes the characters killed were low-level Budapest thugs. Obviously the van they stole is bugged all to fuck. Let's assume it's not rigged to explode, though. Unless they do something like drive the van somewhere and burn it, and then head back to the safe house, I'm going to assume that they get ambushed by a team of security specialists plus two vampires plus fucking Frank, and I'm going to work to separate them.
Now, with that said, I don't think they'll be that stupid. I need them going back toward Jessica Brown. So let's assume that she and Imre saw each other once, she's being held prisoner, Imre knows about that and knows she's in Szeged, and notes that she smelled like coffee.
The characters don't know the book is a fake, yet, though, so that might be the card the conspiracy plays. Get them looking for the book, release Jessica's name as a missing person and maybe some other fictitious bullshit about her being a descendant of the "vampire baron" in the book, and see if they can force the characters into a blind corner. More improvisational, but lets Frank work them a little. Especially if the CIA could get involved.