(Usual disclaimer: I'm a lawyer, but not your lawyer, and not licensed in NC or VA, so don't rely on what I say here as a substitute for legal advice.)

1. I've seen this movie a few times. You want an employment lawyer, preferably one that has done work for tech-company employees and thus likely knows about stock options and restricted stock.

Even more preferably, you want an employment lawyer who has actually tried at least a few cases in court. (Some lawyers are full of bluster but then fold up when confronted with the prospect of actually having to try a case.)

Unfortunately I don't know any employment lawyers in North Carolina or Virginia.

2. Employment lawyers come in two varieties: Management side, and employee side. Some employee-side lawyers get their training in management-side firms and then switch sides and move to smaller firms or one-person shops. I know one or two here in Houston who represent both employees and management (not in the same cases).

3. I wouldn't bother communicating with the old CEO. The person you want to talk to initially, I think, is the CFO of the acquiring company, or its general counsel if they have one.

4. I disagree with Patrick [EDIT: sort of] about the sternly-written letter part. A lawyer who immediately comes in with guns blazing will trigger all sorts of immune-system responses with the acquiring company.

When the dispute concerns a comparatively-limited dollar value, it usually represents relatively low exposure to the company. When that's the case, you want a lawyer who will write a polite letter and ask for a meeting or phone call to exchange views. At least in my experience, that will usually get you farther, faster, at lower cost, and greater odds of being taken seriously, than being aggressive when they don't perceive you as being a real threat to them.

[EDIT: On the other hand, an aggressive lawyer will get everyone's attention more quickly than a polite and reasonable one. It's just that some aggressive lawyers can poison the atmosphere immediately, while others don't know how to tone it down when it comes time to close in on a reasonable settlement.]

5. Never threaten a lawsuit; doing so could let the other side beat you to the punch by suing you in their preferred jurisdiction, e.g., for a declaratory judgment that they're not liable to you. If the time comes when you have to file a lawsuit, then just do it, without anger, rancor --- or warning [1].

(EDIT: But always be ready to file a lawsuit, both in preparation and psychologically; the increased confidence can make it more likely you'll get a fair settlement early.)

6. Start now to gather whatever documents you have that are even remotely relevant --- emails, calendar entries, code commits, etc. Judges and juries tend to place more confidence in contemporaneous documents than they do in after-the-fact testimony. Witnesses might genuinely have "creative" memories, especially if they have an axe to grind, a score to settle, an ass to cover, an agenda to advance, etc.

7. Don't destroy any documents; that can look like a coverup. In court, at best it can damage your credibility; at worst, it can result in sanctions --- possibly including having to pay the other side's attorneys' fees, and perhaps even dismissal of your case.

8. There are some possible "plot twists" that you didn't mention, but that could have a significant effect on the legal posture.

9. Be careful what you disclose publicly (like here on HN); you could be jeopardizing any applicable attorney-client privilege and/or work-product immunity.

10. Watch out for statute-of-limitations deadlines for filing suit; depending on the claims you might file, some of the deadlines can be pretty short.

11. Don't bad-mouth the company [EDIT: or anyone associated with the company]. You don't want them counterclaiming that you libeled them or slandered them.

(N.B. Libel is in writing; slander is oral; and both are "verbal," that is, in words, although I suppose either could be graphic as well.)

12. On the subject of counterclaims: Consider what kind of claims the company might bring against you if you were to sue them. For example, they might come up with a claim that you stole their IP. Or that you did something else wrong. Or that you were terminated for cause. That approach is a standard immune-system response, to try to make you nervous about having some downside and not just upside.

13. I can't represent you in this, but I'd be willing to talk for a few minutes on the phone, off the meter, as long as it's clear that we're not entering into a representation. Shoot me an email; my address is in my HN profile.

[EDIT: 14. Don't use a company computer, email account or phone to communicate about this. The company could be monitoring those comm channels, or it could choose to do so. The case law is still evolving as to whether employees have a legitimate expectation of privacy in those circumstances. In some jurisdictions, communicating with your lawyer over a company-owned channel might jeopardize your attorney-client privilege; as I say, the law is evolving in that area.]

[1] http://www.oncontracts.com/take-a-lesson-from-indiana-jones-...