The most important thing you want to be sure to do with your thesis statement, no matter what the topic is, is to make an assertion. Your assertion is your opinion, the argument that you are trying to prove in your essay.
The thesis statement should also be like a road map for the rest of the essay. It is important to let the readers know exactly what you are trying to prove by writing this paper, and what subtopics you will be addressing. The subtopics will be your body paragraphs in the essay. These are the major points that you will be making in order to prove your assertion or argument.
A literary thesis statement might look something like this:
Shakespeare's use of diction and imagery powerfully reinforce his characterization of Duncan, Macbeth, and Lady Macbeth.
The assertion in this thesis statement is that I am going to prove that Shakespeare uses diction and imagery in characterization.
My subpoints are the three characters--each character will be one of my body paragraphs, in which I analyze how Shakespeare uses diction and imagery to characterize them.
I hope this proves helpful. I would have liked to have been more specific for your topic, but I was not sure which episodes or vampires you referred to in the question.
When you are creating your thesis (the last sentence of your intro paragraph) think about it this way:
__________ (because,but,for..) __1_, __2__,and __3__. Then take each main topic that you made 1,2,3 and make a paragraph out of each topic.
Here is a very vague example:
Dogs are considered to be a man's best friend because they are loyal, intelligent, and can be used for jobs or taks.