The witcher then said to King Foltest: "Pay me, Sire, and I will find your daughter in the dark tomb. I will restore her human form if I can, and if I cannot then I will not hesitate to kill the princess."
The king understood this was his only chance and so placed his daughter's fate in the witcher's hands.
The conjurer struggled with the striga for hours. He warded her off with silver and magic arts. He grappled with the beast and did not let her wound him, but avoided causing serious harm to her as well.
Finally, he locked himself in the crypt, sealed the entrance with magic and waited until dawn.
Witchers possess great knowledge about monsters and know that the rooster's morning call is enough to disenchant a cursed creature