The unnamed narrator reflects on the marriage between his mother (aloof, stoic, saintly, and stubborn) and his father (a vain, promiscuous scoundrel).
He is fixated on eight mysterious months his mother spent in Paris after they split up, when the narrator was a boy: Did she clandestinely reunite with the father?
Did she live out a perennial ambition carefully kept secret? Or did she attempt to sort out another matter entirely, of which the narrator hasn't the least indication?
If he discovers what happened in Paris he might make sense of his parents' relationship, and, in the process, end the nightmares that still recur twenty-plus years after his parents split up.