This is definitely not light bedtime reading - in fact it disturbed my sleep on more than one night. It's an intense difficult book to finish. Unfortunately the 4 main characters spend too much time in marital infidelity, lies & deceit to be likable - even if they are part of the underground war resistance. The dialogue between them is also rather simplistic.
It was interesting to "allegedly" learn about France, 2nd World War & the champagne industry - although who knows what is real or fiction in this book? The writer's use of flashing back & forth between 2019 & the 1940s was an interesting literary technique - although at times difficult to keep track of who is who, when & where.