There was nothing drab about Sheila’s letters, oh no. She detailed her adventures in a looping, gregarious hand and peppered the words and phrases with exclamation marks, as if the tropical climate and lethal spiders and vast horizons weren’t exotic and surprising enough; as if she had to flag them up for her audience in case they missed the best bits. Her traveller’s tales were read aloud to little Alison when the pale-blue, tissue-thin airmail letters arrived addressed to Catherine. If Catherine had ever written back to Sheila, doubtless the tales of life down under would’ve continued, but Alison’s mum was a drinker, not a reader or a writer. She’d only paid any attention to the first letter, and it had made her very cross; Alison didn’t know why. After that, she’d pick them up from the mat and flap them disparagingly, like used Kleenex, and say sour things such as, ‘Heat and dust and bloody spiders. Does she think we’re interested?’ Then she’d drop the unopened envelope in the kitchen bin and later, when the coast was clear, Alison’s brother Peter – older than her by six years – would fish it out from among the tea leaves and peelings, slice a knife though the seal with a piratical flourish, and hold ‘story time’ in his bedroom, reading the letter aloud to his sister, both cross-legged on his bed.

Sheila’s letters filled Alison with a kind of courage and resolve. She kept them as totems, slipping each new one between the base of her bed and the mattress, and when the letters stopped coming, when Sheila stopped writing to Catherine, Alison felt bereft. It never occurred to her that she could have written back herself; well, she was so young, she didn’t have the know-how or the confidence or the money for a stamp, and she was growing up with Catherine for a mother. But she treasured the letters, read and reread them until all the best parts were memorised, so that even when Catherine found the stash one day and put them on the fire to punish her for treachery and deceit, Alison still had them in her mind and could recite whole paragraphs, reverentially, as if they were sonnets or psalms.