Page 53 of Dead Fall

‘You said a neighbour heard gasping. But there was no evidence of her having been strangled or suffocated. It got me thinking about this guy, Jake, who we PM-ed recently. He died of asthma induced by exercise.’ Cassie’s eyes were bright with excitement. ‘His airways closed up and he basically self-suffocated.’

Flyte frowned. ‘But Bronte didn’t suffer from asthma, did she?’

‘No, but we know she had to be careful about what she ate. And it occurred to me, what if she had an extreme allergic reaction to something?’

‘Anaphylactic shock you mean?’

Cassie nodded. ‘Which can close your upper airway within minutes of ingesting an allergen.’

‘How come the Home Office pathologist didn’t see any evidence of it?’

Cassie had to stop herself rolling her eyes. ‘Because without witnesses, or a known history of allergy, anaphylaxis is notoriously difficult to identify. The main sign is swelling of the airway, but that often subsides post-mortem.’

Now Flyte was starting to share Cassie’s excitement. Could this explain something that had always bothered her? Why, instead of killing Bronte in the flat, the killer had thrown her off the balcony, with the risk of being seen by a neighbour or passer-by? According to Chrysanthi, Bronte had to be super-careful about what she ate; if she’d also had a dangerous allergy, that would offer a way to make her death appear accidental. Her murderer could have administered the allergen, and then simply sat and watched as she choked to death. A plan that had gone awry.

‘So how do we prove it?’ she demanded. ‘Reopen the body?’

Cassie shook her head. ‘No point.’

‘Are you saying we can’t prove it?’ asked Flyte, exasperated. Had this infuriating girl dragged her here just to deliver an evidential dead end?

‘No, I’m not saying that. All her samples will still be in the fridge at the lab. If she died of anaphylactic shock there’s a good chance it will show up in the bloods. When the immune system detects a substance it considers alien it produces tryptase, which stimulates the mast cell—’

‘All right, Einstein, I don’t need a biology lesson. So you’re saying we can request testing for this tryptase?’

‘Already done.’ Cassie grinned modestly. ‘Prof Arculus has agreed to sign off the lab requests in the light of new evidence. You just need to square it away your end.’

‘OK.’ Then Flyte’s ever-present frown line deepened. ‘I assume the tests won’t tell us what she was allergic to?’

‘No.’

‘Was there anything in the PM report about her stomach contents?’

Cassie had already checked the original report. ‘Nothing. Stomach contents aren’t even noted at a routine PM unless there’s a bunch of tablets.’

‘So whatever she’d eaten would just have been washed away?’

‘’Fraid so.’

Flyte started pacing up and down. ‘OK, we’ll ask her parents – they would surely know if she were seriously allergic to something. And the ex-boyfriend, that Ethan guy. Although he’s not exactly forthcoming.’

After a pause, Cassie said, ‘I could ask him, if you like?’ – trying to sound casual.

Flyte stared at the pink dots in Cassie’s cheeks: she couldn’t remember seeing her blush before. ‘You’re .?.?. friendly with him are you?’ Her expression signalling exactly what she meant by ‘friendly’.

Cassie made a non-committal gesture.

Flyte hesitated. It was none of her business, but .?.?. ‘Look, we’re friends, right?’

Meeting her eyes, Cassie nodded.

‘I think you should be very careful around him.’ Flyte didn’t like to ask about her pathologist boyfriend, the one she’d been living with. Was she being unfaithful? Somehow she couldn’t see it.

‘Why? He’s not a suspect is he?’ Cassie’s heated tone and lifted chin warned Flyte that there were limits to their friendship.

‘Not officially, no. But think about it. Whoever killed Bronte had to be close enough to her to know what she was allergic to. Which means we can’t rule out any close contacts including Ethan and her father.’

‘Or her mother,’ said Cassie.

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