For the most part, Marcel is with Albertine but doesn't want to be with her ("The Captive"), but once she's gone ("The Fugitive") he's obsessed with her again, madly in love, until he learns of her sudden spoiler alert. Most of the musing seems to be about whether Albertine is getting it on with women. The finest section, up there with the description of the grandmother's death, describes Albertine asleep. It's not riveting but it's surely real good and maybe even the best ever. Other bits take off, especially about music and Venice but they're not as clear as the bit about Albertine sleeping. When Proust's prose clarifies an image, be it a little phrase in a concerto, pink hawthorns, an airplane rising into the sky, or his lover asleep, he's the best.