How do I get the mandrake root from the graveyard?

Hint 1 of 6:

Have you talked to the healer yet?

Hint 2 of 6:

She should have told you about the root and how to get it.

Hint 3 of 6:

It's important to pick up the root at midnight.

Hint 4 of 6:

You will also need protection from those nasty ghosts.  Once again, the 
healer knows something about that.

Hint 5 of 6:

In fact, she sells that protection for you.

Hint 6 of 6:

Once you have enough money, you can buy some undead unguent.