Chapter 1 - 3
1st Wisp - Croakwood (west of Ink Portal)
answer ("I didn't take your name" and next "No, but Katarina knows it. Don't you?")
2nd Wisp - Dreadworks (south-east of Secret Lair Entrance)
answer "Death"
3rd Wisp - Old Town ( east of Ink Portal, north-east part of the map)
answer "42"