Summarise a Chapter Into Five Key Points

You read the chapter, nodded along, and could not now explain it to save your life. This condenses it properly: the one idea it is built on, four supporting points, the new terminology, and the one thing you still do not get, all in your own words rather than the author's.

<context>
You have just read a chapter in a textbook or book and want to condense it into a compact summary you can review quickly before an exam or meeting.
</context>

<task>
Summarise a chapter you have just read:
1. Identify the single most important idea the chapter is built around
2. List the four supporting points or pieces of evidence
3. Note any terminology or concepts defined in the chapter
4. Identify one thing you still do not fully understand
5. Write the summary in your own words, not copied from the text
</task>

<output_format>
- Five-point summary (2-3 sentences per point)
- Vocabulary list: key terms with one-line definitions
- One open question to investigate
- Length: 250-320 words
- Tone: concise and precise
</output_format>