Chapter Thirty-Three

Althea Knowles came back re Bronte's school medical notes the next morning while Cassie was making her morning coffee.

‘There's nothing on file about a serious allergy, or any allergy come to that. I always made a note of her stomach issues and kept her parents informed but I don't know what, if any, action they took: the notes say they used a private doctor for everything, even vaccinations.' Mrs K hesitated. ‘There was something in there I'd completely forgotten though. But you really can't share this.'

‘Absolutely not,' Cassie assured her.

‘The previous nurse made a note right at the start of her Year 7 when she arrived here. She had a sibling, a twin brother who died at the age of three.'

Cassie remembered Bronte's father George telling her about Alexander. ‘Did it say what of?'

‘Beta thalassemia. It causes a haemoglobin deficiency that can be fatal in the early years.'

After hanging up Cassie went straight to her medical textbooks. An inherited genetic abnormality, beta thalassemia major was indeed a life-threatening condition requiring lifelong blood transfusions, and some children, like Alexander, didn't survive to their fifth birthday. But it wasn't much help in getting to the bottom of Bronte's death. Bronte had been a female, non-identical twin and clearly hadn't inherited the condition, and anyway there was no association between beta thalassemia and severe allergy.

*

An hour later, at work, she got an email from the tox lab at Imperial. They'd run the tests on the sample of Bronte's femoral blood stored in their fridge. The normal range of mast cell tryptase was between 3 and 5 nanograms per millilitre; Bronte's was off the scale at 41.4.

Cassie forwarded it to Flyte and less than two minutes later her phone rang.

‘Is it reliable?' asked Flyte without preamble.

Cassie grinned. ‘I'm fine, thanks, Phyllida, how are you?'

‘Yes, OK, fine, how are you, etc. So, would it stand up in court as proof that she suffered anaphylactic shock?'

‘I'm no expert, but it should do. Tryptase levels can increase post-mortem but this is so high it looks conclusive.'

‘OK, good .?.?. Of course, proving she had an anaphylactic reaction doesn't help unless we can prove someone fed it to her and then tipped her over the balcony when she started choking.' She paused. ‘But how would the killer get Bronte to eat or drink something to which she was allergic?'

Flyte's old-school grammar made Cassie grin. ‘Good question. Apparently the severity of reaction will be worse according to how big a dose of the allergen you're exposed to. But you do hear of cases where even the tiniest trace of peanut, say, picked up during food prep can kill you.'

‘So even a tiny bit sneaked into her food or drink might be fatal,' Flyte mused. ‘The key isn't so much finding out what she was allergic to but establishing who knew.'

‘Yeah. Any progress on a suspect?' Cassie asked.

‘You know I can't discuss that with you,' she said stiffly before saying, ‘I will tell you this. You are not to discuss any of this with Ethan Fox. Is that understood?'

*

A few minutes later, Cassie called her dad, Callum, in Belfast. ‘To what do I owe this honour?' he said, with that ever-present smile in his voice.

‘I'm sorry, Dad,' she said. ‘It's just been stupid busy at work, and .?.?. you know I'm not great on the phone. How's it going over there?'

‘Good. Yeah.' The sounds of kids shouting excitedly in the background came over the line. ‘It's been great seeing the wains, you know? We're about to take them to the seaside.'

‘Really? Is it warm over there?' Northern Ireland wasn't known for its Mediterranean temperatures, especially in March.

‘I'll have you know it's getting on for fifteen degrees. Roasting.' A soft chuckle.

‘Do you remember taking me to Marine Ices?' she said, feeling suddenly nostalgic. When she'd been little, with her mother spending a lot of time in bed with depression – or a hangover – it was her dad who'd done the lion's share of the parenting.

‘Of course.'

‘What was my favourite flavour?' Testing him.

‘Rum and raisin.' No hesitation.

‘Aha, so you're to blame for giving me the taste for alcohol,' she told him.

‘What was mine?' he asked, cunningly.

‘Come on, I was four!' she protested. ‘Umm .?.?. tutti-frutti?'

‘Impressive! You always did notice every little thing.'

‘It's .?.?. good to hear your voice,' she said, biting her lip – after so many years without a dad this stuff still didn't come easy to her.

‘I love you, Catkin.'

A little surge of panic. But after a moment she found her voice. ‘I love you too, Dad.'