What to do: PI lied to me and is keeping my grant! I've written 14 grants for my principal investigator (PI), from conception to writing the entire thing, which has resulted in over $10 million in funding for my PI. 

I refused to write any more grants for him; however, he threatend to fire me if I didn't. I was fine with that, at which point my boss told me that if I wrote the 14th grant and we got it, I could take it with me. 

Well, I did and we did get it. 
Now he's refusing to give it to me, threatened to fire a technician/friend of mine, and has insisted that we got the grant because of his name (not the idea/grant itself). He knew his name was there from the beginning — how can he argue that at this time? This grant would have been submitted as a K99 for myself, but instead I had written another, independent grant thinking I'd have two shots to get a grant. I didn't get the K99, but the other grant should be mine.

This is/was my key to obtaining a faculty position. I also have previously filed an initial patent form indicating that the idea was conceived and developed by me. I'm on the grant as co-investigator (my boss said I cannot be listed as a Co-PI since I work in his lab) but no budget has been given in my name. 

What should I do?
I believe that you need to obtain qualified and competent legal advice, not just anonymous advice from a Stack Exchange site.

However, there are some obvious things you can do:


Make sure you have meticulous records of everything you claimed, including the previous grant proposals, showing that you were the one responsible for their execution.
You really need to have some form of hard evidence that the PI promised you could keep the grant you earned.
Make sure everything you do from here on is also documented. 


But this is a tough situation, and I'm not sure what your options outside of the legal system will be. You might also want to contact the grant sponsor to see what your options are.