Another Stinking Copyright Question

I made plans to cowrite a screenplay with another writer. I was mid-way through the first draft when we decided to work together. He has a great dialogue voice that I felt would work well for the script.

Our agreement was that I would finish the first draft, then pass it to him. He would put his spin on it and pass it back to me, etc.

After I finished the first run, I copyrighted it and registered it at WGA, since it would be on Zoetrope, etc. I copyrighted it in both our names.

Before he did any work on the script, he and I got into a personal dispute and abandoned the partnership. The script is entirely my work.

However, being (apparently) a bad person, he refuses to abandon his half of the copyright. His reasoning? "Because I don't have to."

So my question is: Do I have any recourse here?

I'm gusessing that I don't , but I'm hoping someone might have an idea.

Did he ever get a copy of the script? If he can't even produce a copy or qoute lines from it then it should be obvious he hasn't had any input. However, once the script goes public and he could get a copy it becomes moot, so you'd have to deal with it now.

Did you sign a collaboration agreement? Did it make any provision for the assignment of copyright? Did it make any provision for the failure of a party to contribute to the work? This is why such agreements should be drafted in writing and signed by all the parties involved. A lawyer could be consulted if your erstwhile partner has not fulfilled his part of an agreement.

If you registered the copyright in both names, you are now co-owners. If you wish to proceed with a new draft, I'd suggest registering any subsequent versions with the WGA in your name; but, to divorce your work from something with a jointly held copyright, you're facing a complete re-write.