Even his staunchest admirers would concede that Martin Amis has dropped some clangers over the years. But Time’s Arrow, his novel exploring the Final Solution, wasn’t one of them. Nominated for the 1991 Booker, it’s a sombre, vivid exemplar of a type of writing that can look presumptuous at best and be exploitative at worst. Most novelists would have returned with relief to less treacherous topics as soon as the proofs went back to the printer. But not Amis: 23 years on, he’s tackling the subject again, in a book framed by his publishers as – wait for it – a “Holocaust comedy”. What on earth possessed him? “Very cautiously,” he writes in the thoughtful afterword to The Zone of Interest, “I submit that part of the exceptiona