In reality they probably shouldn’t bicker that much while being this close to the person they don’t want them to notice … but hey, it’s my story. They’re as quiet or loud as the plot needs them to be ;)

↓ Transcript
Shara: <whispering> Did you get where book is?
Katharina: <whispering> Not the exact room ... but he has to be somewhere right below us!
Shara: <whispering> Careful, I don't trust this roof ...
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<they spy through a crack in the roof and see Book, still a bag over his head and tied to a chair. In front of him is one guard>
Shara: <whispering> ... I got him! And there's only one guy with him. But I bet there's more right outside the door ...
Katharina: <whispering> So how do we ...
Shara: <whispering> As soon as I give a sign, you BLAST A HOLE THROUGH THE ROOF, then go down and SEAL THE DOOR.
Katharina: <whispering> B-but that man -
Shara: <whispering> I'LL take care of him. CAN YOU DO WHAT I JUST TOLD YOU?!
Katharina: <whispering> ... yes.
Shara: <whispering> Good.
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Katharina: <whispering> ... sounds like we won't have a lot of time ... ?
Shara: <whispering> That's where I hope our GOOD CAPTAIN will come through with the distraction. We just need a few moments ...
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Shara: <whispering> By the way: I assume you'll be able to get us DOWN the same way we got up? Including your boyfriend?
Katharina: <whispering> I ... assume that, too, yes.
Shara: <whispering> ... KAT ... ?
Katharina: <whispering> WHAT, I'VE NEVER DONE THIS BEFORE!