The daylight has faded to a smoky grey, the low-hanging clouds threatening rain. The harsh interior lighting of the concourse makes her wince as the automatic doors slide open. She glides her new wheeled suitcase towards the check-in desks, feeling light, at last, after finally ditching the rucksack. It had been a cheap buy from Mountain Warehouse, she and Laura buying the same ones in matching colours. Giggling as they’d picked up and put down the weird little camping and hiking trinkets on display near the tills. Laura’s rucksack will still be pristine – probably still in the cellophane. She hopes they’ll get a chance to use it together some day, although she’s not sure that another backpacking adventure is going to be on the cards for a long while yet.

God, she misses Laura. Can’t wait to take the piss out of her pale, scrawny leg, free of the plaster-cast at last – just in time for her getting back home. There’s so much she needs to share with Laura, about everything. But there are some things that will have to stay locked away for good.

Violet thought she knew the full story, reading those emails about Greg that she was never going to send. Yes, she did hit him. No, she’s not proud of it. But after what happened, it was him or Laura who was going to have to face her rage – and she cared more about Laura. She didn’t want to destroy their whole friendship over a man. Certainly not a man like Greg.

That’s why her fall had to look like an accident.

‘Where are you flying to?’ the neatly made-up woman at the check-in desk asks.

‘Edinburgh,’ she says. ‘Oh no, sorry. It’s via London.’

The check-in woman smiles. ‘That’s fine. I can see it’s with one of our partners. I can check you straight through.’ She taps away on the keyboard, and Carrie examines the little sign with all the prohibited items on it. The gas canister reminds her of the day that she and Laura bought the rucksacks.

Carrie had gone home to dump her shopping and get changed for their usual Friday night out – it was only a week until they were due to fly out on their trip of a lifetime. The message had pinged in while she was finishing her make-up, the phone sitting on her dressing table. She didn’t recognise the name of the sender, and there was no profile photo. Normally she would just delete messages like this, but something made her open it. A moment after that, the photo appeared.