Juliet tells Sophie to burn this letter after reading it. She admits that she has loved Dawsey from the moment she arrived, but has been trying to be calm about it. However, last night, Dawsey came to borrow a suitcase for his trip to collect Remy. Kit was asleep, so Juliet and Dawsey walked out to the cliffs and watched the sea. Juliet desperately wanted to take his hand. Dawsey turned to her but before they could kiss, Mark arrived.
Watching the sea with Dawsey helps Juliet realize that she's actually in love with him and her heart isn't beholden to Mark. It's also important to note that Dawsey is attempting to get closer to Juliet while he's caring for Remy, which again shows that for him, caring for others lets him connect to even more people.
Juliet wanted to kill Mark but greeted him anyway. She felt queasy as she introduced Dawsey and Mark. Dawsey left and Juliet tried to seem happy to see Mark. She convinced him to take a room at the hotel. Though he went, he wasn't pleased. Juliet's been chewing her fingernails all night, wondering what to do about Dawsey. She doesn't want to make a fool of herself and wonders why she cares so little for Mark and so much for Dawsey.
Though Mark's visit is poorly timed, it does make it clear to both Juliet and the reader that she's not in love with him—if she were, she would've been happy to see him. Her remark about not wanting to make a fool of herself suggests that she still believes that marrying Mark is the right thing to do, even if he's a bully.