The night in question by Susan Fletcher

Florence Butterfield has lived an extraordinary life full of travel, passion and adventure. But, at eighty-seven, she suspects there are no more surprises to come her way. Then, one midsummer’s night, something terrible happens – so strange and unexpected that Florrie is suspicious. Was this really an accident, or is she living alongside a would-be murderer? The only clue is a magenta envelope, discarded earlier that day. And Florrie – cheerfully independent but often overlooked – is the only person determined to uncover the truth. As she does, Florrie finds herself looking back on her own life – and a long-buried secret, traced in faded scars across her knuckles, becomes ever harder to ignore.