Final answer:
The obsession with Georgiana's birthmark by her husband Aylmer almost ruins their evening and represents a central symbol of mortality in Hawthorne's 'The Birthmark.'
Step-by-step explanation:
The book 'Unwind' does not appear to match the given excerpts, which seem to be from Nathaniel Hawthorne's short story, 'The Birthmark.' The passages talk about Aylmer, who becomes obsessed with a small birthmark on his wife Georgiana's face, seeing it as her single flaw in an otherwise perfect visage.
Instead of bringing them closer, Aylmer's fixation unfortunately ruins the evening and other moments that should be joyous by constantly reverting to the topic of the birthmark. The 'crimson hand' of the birthmark becomes a central symbol of mortality and imperfection that Aylmer cannot ignore.
In a different context, a tithe refers to a one-tenth part of something, paid as a contribution to a religious organization or compulsory tax to the government. However, this term is not directly relevant to the text in question.
A tithe is a term used elsewhere to describe a one-tenth contribution, but it's not pertinent to this particular story.