[emacsen]

A +1 to everyone else who has said get a lawyer.

I'll add another angle: financial.

You have invested years of time and presumably thousands of dollars into your schooling. Their threat that they will not allow you to graduate unless you give them unpaid labor without a clear boundary condition is a threat. While I haven't seen the correspondence, from what you said it appears they're doing the moral equivalent of one of those sitcom situations where someone is compelled to do what the other person wants under a threat, and even when they've done it, the threatening person keeps the threat.

A good lawyer (and not all lawyers are good) will help you understand your rights and your position.

As others have said, this is not an escalation of aggression, and not only don't you have to tell them whether you've seen a lawyer, unless the lawyer is speaking on your behalf- you don't have to tell them anything, and you shouldn't tell them, or tell us (in case they read this, which they likely will).

A lawyer in this case is more of a scholarly resource, telling you what your options are.

[thih9]

Agreed.

To add to that: it is understandable to expect and hope for the other party to behave rationally. But there is a power imbalance that the other party is exploiting and for all we know intends to continue.