Ok, I figured it out.
The are two parts of the game. Part1 (ch1-6) Part2 (ch7..)
Few posters suggest pt1 is boring and it can be skipped.
You can skip, I did, but you are going to be a little in the dark about what is going on. And the fact that starting an investigation requires you to manually type in names doesn't help..
Anyway, the key to getting Dorothy is starting the investigation. Simply call 'Dorothy', follow the dailogue and invite 'Anna' and then 'Dorothy' again. Everything else will fall into place.