Green: add

Red: delete

Blue: comments

1) Mrs. Miller, an ex-nurse working with the Boyles, counts of on new nurse Laura’s help the new nurse to find the key of her chains from Laura‘s new boss/lover. Trouble is: Laura might be the one who chained her. I don't really know what's going on here. Who are the Boyles? What chains are on Mrs. Miller? The missing commas also made it harder to read, so make sure your grammar and punctuation are tiptop. Also, who is your protagonist? The way this is phrased, it seems more focused on Mrs. Miller.

2) Nurse Laura a nurse vowed to help Mrs. Miller, an ex-nurse chained and tortured by Laura’s new boss/ lover Mr. Boyle inside a hidden basement in his castle. But nothing is ever as it seems when Laura finds out her real identity: Mrs. Boyle. You're heading in a better direction. Things are still pretty choppy, though. The underlined portion is all one dependent clause, and it's not the easiest to read. In your last sentence, the antecedent to "her" is technically unclear: I assume "her" is referring to Mrs. Miller, but grammatically it's referring to Laura. From this pitch, I'm guessing Laura is the protagonist.

3) Nurse Laura a nurse leaves her only friend Elizabeth to work Iin the Boyle’s' castle. In her first week she discovers a secret basement where the ex-nurse is chained and tortured for a year by Laura’s new boss/lover. Problem is Laura doesn’t know the ex-nurse’s real identity: Elizabeth. From the first sentence, it sounded like Laura was leaving and Elizabeth was staying to work for the Boyles. Again, you have an unclear antecedent with the "her" in your second sentence. Grammatically, is it referring to Laura or Elizabeth. This pitch also raises the wrong sort of question for me: How does Laura not immediately recognize her only friend when she finds her?

4) In her first week as the new nurse, Laura discovers a hidden basement where the ex-nurse is chained by Laura’s new boss/lover. Laura faces an impossible choice: Helping the ex-nurse and losing her lover, or risking being the new victim. This is definitely your best pitch. It's the clearest in setting up the situation and presenting stakes. However, if I hadn't read the previous pitches, I would probably assume that Laura was starting her new job at a hospital, not someone's personal nurse. I also do have to ask why Laura is worried about losing her lover. One, that seems contradictory with helping the nurse, because I would assume helping the nurse would lose Laura her lover, but, two, why would she still want him? If I found the guy I was with was keeping someone chained in the basement, the last thing I would worry about is whether he would still want to be with me if he found out I helped said person escape.

Honestly, I think your first three you can just scrap and start from fresh. The fourth one you can probably still workshop for a bit. If I have to guess, I think that you're so engaged in your story that everything makes sense to you, but you have to remember that we have no context, so it doesn't make sense to us. It's hard to take a step back sometimes. Start simple with your pitches. The rough formula I've been given before is (CHARACTER + GOAL) + (ANTAGONIST + OBSTACLE) +STAKES. So, Laura wants to work for and love this guy, but he's locked the old nurse in the basement, and Laura might be the next victim. Plug and play as needed.

Also, make sure your grammar/punctuation are solid. There's a bit of leeway in Twitter pitches because of the character limit, but you have errors with commas and apostrophes, the former of which also make reading difficult. Those sorts of things need to be cleaned up.

If you post revisions, I'll take a look at those as well.