I would be freaked out if saw as much blood in one day as Reagan did too! Wouldn't make me thirsty though. If it was milkshakes, different story entirely.

This was pretty good. I like how you tricked us into thinking Reagan had a phobia when she was actually scared of what she would do. And it seems like it might have been a relief when her sister showed up to kill her.

There's been a lot of vampire films throughout the years, and it's hard to make any story of the undead seem fresh, but you did it. Good work.

On the go notes:
I love the opening visual since I'm already aware this is going to be about blood. Well done!

Code "As average as they come"

Try not to use this as a description ever. Most readers will judge you that there is no actual point for him to be average, and you are just being lazy and skipping your characters' descriptions duties.
A kiss on the forehead? That's weird. I'm weird I guess.
Who is her that she needs to call? Why does she want to avoid that? Sweet! A mystery. I like it.

Code "She fondles the locket."

You are using body language to express that she's nervous about this issue. Man, you're good.

Code "Drops of blood hit the floor, exploding into a shower of tiny red particles. Hypnotizing."

Love it! True master.

Code "It pains her to hit the ignore button."

Now you are being lazy, man. Describe how she expressed that pain. Don't just tell us.

Code "Blood gushes down her thighs and calves."

You sadistic maniac. You're giving Reagan hell and I loved it :')

Quoted Text "After I was attacked that night, I did all the right things. Went to the hospital, filed a police report. Even counseling. How could I have known any of this would happen."

Hmmm. Heavy exposition that wasn't skillfully handled.

Holy shit! What a reveal! Goddamit. You are so good.

Quoted Text "The true fear is what I will do if I give in to my thirst. Now I know, I will never be at peace until I become who I am truly meant to be."

Come on, man. We got this. Trust our intelligence. Heavy exposition again.

Code "It’s no secret the bartender is being eaten behind the bar."

Heavy exposition again. I'm offended.

Rest in peace! Beautiful.

Overall:
I loved the twist. It made everything worthwhile. The concept is promising. And a serious attempt at perfectly executing it will render a truly entertaining script and eventually a masterpiece of a short.

Characters:
None of the characters has the depth I hoped for. The short exchanges between them and the monocolored situations you put them in, gave us no insight into what kind of people they are. Reagan is afraid of blood and guiltily avoiding her sister. That's all. James is a teaser who care about family. Cass loves red syrup flavor and would rather avoid her sister. As you can see, there is hardly any depth to them.

Also Reagan change of heart at the end felt unatural and not paced right.

Dialogue:
I try to avoid criticising dialogue when there is a characters' problem. But I would say you need to work on your dialogue. Less exposition, more entertaining and fun to read.

Structure:
I hoped the reveal of Reagan true fear was the middle point, not that close to the climax. What if Reagan ran away from them, and we spent the other half of script chasing her? Wouldn't that be more entertaining? I agree that the 12 pages limit is making it difficult to explore this concept in such way.

Story:
Loved the story because of the twist and the last bit of action we got. And the second reveal was also good. Cass and James being hunters. But I thought the part before Reagan's thirst reveal was very placid. You just put her in bad situations. And I hardly cared for her. So those scenes did nothing for me on an emotional level.

Advice:
- Work on your characters. Give them depth and make us care for them.
- Rearrange the reveals. Put the thirst reveal in the middle, and the hunters reveal on the start of the third act. Pace it in a way so we can enjoy it one bite at the time. Don't cram it in the last act.
- Improve the dialogue. Beware of your heavy exposition habit.

Best of luck.

I want to start it off by pointing out that I'm a huge fan of the action lines.
Great cinematic feeling.
I like the way you introduced the characters and expressed Reagens illness.
The twist was for me a litte too far fetched, but I still accepted it.
What I don't like that much is the fact how easily Cassidy ends the life of the only piece of family we were introduced to and that she was prepared to kill that beast.
But hey, why not?
You gave the story definitely a new angle, so great job!