Note cards are used to organize information when you´re starting a research paper. The information gathered there could be categorized by topic. When you find an interesting fact about the topic you should writing down paraphrasing it. For each topic, you could have as many cards as you want but each one must express only one idea extracted for a source.
There are four items that the note card must have: Topic, Where you found the information, paraphrased information extracted from the source, source´s page.
Steve is defensive especially now that Don has pointed out that nobody knows what he has been doing in the basement. The evidence suggests that Steve is going to get angry at Steve for accusing him of causing all of the strange goings on in the neighborhood. To Don, this anger is more evidence that Steve is up to something.