- Dorothea wasn't really annoyed with Will for coming – she was sad that Mr. Casaubon ignored him, and that's why she looked uncomfortable.
- Dorothea usually spends Sunday afternoons reading, but she can't get into any of her usual favorites.
- She feels like her life is empty, and that she'll never see Will – or any other person in the outside world – again.
- After dinner, he asks her to read his huge volume of notes out loud to him, and mark the places where he stops her.
- This is part of the "sifting" process – he wants to go through the notes and research he's made over the years, to finally get going on the book itself.
- Dorothea suspects that he's finally decided to start putting the book together because Lydgate warned him that his health might not last.
- He even wakes her up during the night to continue working on it by candlelight, and Dorothea doesn't complain.
- Before they go back to sleep, Casaubon asks her to make a solemn promise: if he dies, she has to swear up and down not to do anything of which he would disapprove.
- Dorothea is shocked that he'd ask her to make a promise like this – doesn't he trust her?
- She hedges for a while, and finally asks that he let her wait until the next day to make the promise.
- She wants to sleep on it.
- She imagines that he wants her to promise to finish sifting through his research, and publish his book, after he dies.
- It's not work that she enjoys, and she can't imagine wasting years on a project that she didn't even begin.
- But then again, he's spent years and years on this already, and to tell him that she's going to throw away his work as soon as he's dead seems cruel.
- At breakfast, she tells Casaubon that she'll meet him out in the garden to give him her answer: she's decided to say yes, and is pretty miserable about it.
- When she gets to the garden, she finds him sitting with his head down on a table.
- He's dead.
- And Dorothea faints. She comes to with Lydgate at her bedside.
- She's delirious, and can't stop talking about the promise.