You went with Geralt to Toussaint to catch the beast. You met Regis there, and since you were very fond of vampires, you often stayed alone with Regis. And when in the house in Port, Regis had to wait for Detlaff and Geralt went to the Princess, then you were left with Regis. Night came.. Regis was again ill after that experiment in the 'prison for vampires' and he decided to fly to the cemetery(his home). When you were left alone, red smoke suddenly appeared on the floor, and Detluff suddenly appeared....

Detluff: "What are you doing here...?"

He asked in a cold tone, crossing his arms and looking at you..