Plot v incident: Do novels need to have a plot?

Jennifer Clements's Prayers for the Stolen continues with its nearly surreal, horrific accounts of the miserable fate of the young women in rural Mexico prey to the drug lords - the narrator, Ladydi (family nickname?) tells of the arrival of men in SUVs, her mother telling her to run for shelter in one of the holes she's dug in the ground, narrator huddled underground among spiders and scorpions while the men frighten her mother who insists there's no daughter on the premises, the men later go to the house of friend Paula, known as a real beauty, kill all the guard dogs, abduct her; some months later Paula returns, traumatized and barely coherent, sitting on the ground, covered with black ants, she tells Ladydi about her captors, she's marked her body with cigarette burn, allegedly to show anyone who finds her corpse that she's an abductee - but also, we sense, out of shame and despair - and on it goes, an incredibly sorrowful novel that, sadly, has the ring of truth about it. The only thing missing, I'm afraid, is any sense of plot: Clement gives us a series of sketches and loosely linked events in the small town in state of Geurrero (?) - arrival and departure of the school teacher, closing of the one beauty salon when the owner, Rosie, disappears and of course the last thing you'd do is tell the police, breakup of Ladydi's parents when mother surmises father is having an affair w/ co-worker at Acapulco hotel poolside bar, etc. - but at least to this point, about half-way through, there is no arc to the story and no particular character development. Perhaps novels don't need to have a plot, but, as a friend succinctly put it in a writers' group, readers like plot - and compilation of incidents, no matter how powerful and evocative, does not provide the same sense of movement, growth, conclusion that we anticipate in a novel.