He will send her head flying.

' Bloo...Blood of a Siren?' Ginny thought like she was hearing things, there was no way the duke said those words right? But when she stared at the Duke to smile at her and then say ' Got you! I was just joking' but after a short while when he didn't say anything and Ginny came to the realisation that the chances of Duke Akris saying anything like that were just as small as her being able to speak without causing a downfall of a country. 

But she still swallowed as she picked up the paper and scribbled —— 'Blood of a siren?'

Duke Akris raised a brow and nodded, " I believe that's what I said didn't I? Don't tell me that you are deaf along with mute." 

In the current circumstances where her life was in more danger, Ginny decided to let that small comment slide as she wrote in a hurry. ' But why a Siren there might be other options as well? Right?'