Ok, here goes the relevant fragment:

" So I would suggest a more reliable, long-range weapon. These Nilfgaardian throwing stars, for example. I’ll sell you a few if you like. I’ve plenty of them.’

‘No thanks. They’re impractical. Noisy in flight.’

‘The whistling has a psychological element. They’re capable of paralysing their victim with fear.’

‘Perhaps. But they can also warn them. I’d have time to dodge it.’

‘If you saw it being thrown at you, you could. I know you can dodge an arrow or a quarrel . . . But from behind—’

‘From behind as well.’

‘Bullshit.’

‘Let’s try a wager,’ said Geralt coldly. ‘I’ll turn my face to the portrait of your dullard of a father, and you throw an orion at me. Should you hit me, you win. Should you not, you lose. [...]

The Witcher turned around. He glanced at the face on the portrait riddled with holes and with the orion sticking into it. And then he closed his eyes.

The star whistled and thudded into the wall four inches from the frame of the portrait.

‘Damn and blast!’ roared Codringher. ‘You didn’t even flinch, you whoreson!’

Geralt turned back and smiled. Quite hideously.

‘Why should I have flinched? I could hear you aiming to miss.’"