Onie is about thirty, just passed her driving test and bought a new car, although she gets lost and her car engine is enveloped in smoke. Onie has been a dancing partner to the quite well-known Endel, until a fall from a ladder ended her career. Uncle, when he died, left Seaside Hôtel on the island of the same name to Endel, who as a kind of consolation has given the hotel to his former partner Onie, who ends up asking Lolie for help.
Lolie (who bears little resemblance to Nabokov's Lolita) has lived all her life in a bungalow which used to take in paying guests, but which now (unlike before) doesn't seem to get anyone in broken-down cars, people forced by circumstances to stay the night, abandoning their worthless heaps. So she just exists there with her very old grandmother, can read and write so doesn't have to go to school, but is missing human contact: her grandmother sleeps increasingly during the day, and the 'husband of [her] mother' (so her step-father?) is becoming increasingly absent, maybe even (the reader might imagine) drowned.
So Lolie welcomes Onie as a possible very rare guest, and Onie begins to teach her to dance. A 'young man' of about twenty appears on a motor-bike, having also lost his way. He wanted to film Seaside Hôtel, which was very popular during the silent movie era, but says now all that's left is the façade, the rest has crumbled away. And of Onie's hopes for its revival, there is obviously nothing left.
After he dances with Lolie (who does it with a different style to Onie, and who has recently begun menstruating) they disappear inside the bungalow. Early next morning Onie has buried Grandmother, whom they recognised had died the night before, and Lolie tells her that she had sex with the young man, who left soon after, and mentions a different kind of blood, but still naturally spilled.
Unable to fulfill her wishes, Onie drifts off on a small boat and Lolie and the grandfather (who isn't really the grandfather, but who cares?) push the new car with the bust engine down to the boathouse where the grandfather lives with other (much older) abandoned cars and who also dies shortly afterwards: that final push of the car has caused heart failure. And Lolie hitchhikes off (she hopes) to take more official, more different, dancing lessons: she's still a minor so can't officially run the four rooms in the bungalow, but she will return and give much more satisfaction – again, of a different (and expensive) kind, of course – to her paying guests. The new name of the bungalow will of course be 'Seaside Hôtel'.
Links to my other Marie Redonnet posts:
Marie Redonnet: Rose Mélie Rose | Mellie Rose
Marie Redonnet: Nevermore
Marie Redonnet: Tir et Lir
Marie Redonnet: Mobie-Diq