See the Update below.
A book described by Reading Matters as a love letter to Paris that is set in the mid-1960s is irresistible. She did also emphasize that it is very mysterious and that too was true.
The narrator is Jean, looking back on a few days when he was 18 and his father had just fled the city (for mysterious reasons) and he was on his own as his mother was somewhere in the south. The apartment where he lived was also occupied by a man who had worked with his father. Jean was selling valuables to survive to a kindly man who volunteered to help him resettle in Rome.
He met an older woman (22 years old) when he saw her questioned by police just after he was asked by them about people he did not know. She fell in with him and they drove around on various errands in Paris and environs. The time is the mid-60s and the locations and atmosphere make you think of the film Breathless. Oh, now that I've read the Wikipedia entry on the film, I imagine this book was inspired by it.
Jean tells us that the man who had long worked for his father (Grabley)
in the office at 73 Boulevard Haussmann, must still have been organizing those "papers" whose existence I hadn't even suspected. I had always thought the premises were as empty as the inkwells on the desk and that my father occupied them like a waiting room. And so I'd been surprised, thirty years later, to discover a tangible trace of his presence on Boulevard Haussmann, in the form of that envelope with the name of the ore refining company. But it's true that a name on the back of an envelope doesn't prove much of anything: you can read it over and over, and you're still in the dark.
Which is where we remain. Jean and the woman named Gisèle spend time with several men she knows and are asked to do them a favor that Jean realizes makes them an accomplice to some bad, perhaps violent act. When that has been done, the two men disappear and Jean and Gisèle make plans to leave for Rome and a new life.
Before they leave Gisèle sends Jean into a cafe to seek news from a man behind the bar about her friends. The man says only they have left but will be back. Gisèle then tells him she knew the man at the bar when her husband worked for the Winter Circus. Ten years later Jean went into that same cafe and found the same man behind the bar. He sees photos on the wall of performers from the Winter Circus including a picture of Gisèle.He questioned the man about Gisèle, her husband, and her two friends but did not learn much. The man asked if he was still in touch with her. Jean leaves shortly after that question and tells us, "Once alone, on the boulevard, I stupidly broke down in sobs."
Update: I happened upon a review in the New York Times of Modiano's memoir and a trilogy that was very enlightening. The memoir and all his novels are about his "postwar French childhood spent carelessly shuttled between indifferent parents." Another enlightening description: "Modiano's narratives stage the past as a series of mysteries and invite his readers to follow clues with him. But there will be no answers. The more he, his characters, his readers attempt to put the pieces together, the more fragmented the big pictures becomes." Perfect. His memoir was translated after he won the Nobel Prize in 2014.
Patrick Modiano, After the Circus, trans. Mark Polizzotti, Yale University Press, 2015, 216 pages (I read the kindle version). Available in the UVa library in French.