How do I get the Sunstone? [T]

Hint 1 of 14:

If you talk to Sophia, you should find out that you need to trick
Trottier into giving it up in a seance.

Hint 2 of 14:

Once you find Trottier, make sure that Indy doesn't patronize him.

Hint 3 of 14:

And make sure you've read enough of the Lost Dialogue that you can
answer the question he asks you.

Hint 4 of 14:

Once you've managed to talk to Trottier, you will need to scare him
into up the stone.