Gillard nodded. ‘I understand from the police in Taipei that he isn’t married, and that you are his only living close relative. I assume since you live in Australia that you didn’t see him that often.’

She nodded. ‘He divorce, long time ago. No woman for long time. But I no sure. We too far apart. I live here with my son and daughter. Better with no big communist next door like in Taiwan.’ She smiled.

Gillard knew that the next part would need to be done with the utmost delicacy. ‘Mrs Ho, were you aware of any plans that your brother had made for his own death?’

There was a pause at the other end and he saw her blink numerous times. ‘One time when he depress and call me, he said he go to Switzerland and go out nicely. I beg him no, there always hope. He had money. Could go America for treatment. He no mention it again.’

The detective noted down details of when Dr Chen’s sister had last seen him and any friends and neighbours he had in Taipei who might have a better insight into his mood immediately before he departed for Britain. He once again thanked Mrs Ho, asked her to forward the details of any local police liaison officers who were helping her in Australia, and said he would be in contact again. He knew that it was likely there would be upsetting details that would reach her at some stage, and he was anxious that she shouldn’t have to deal with it alone.

While Gillard was on the call DC Rob Townsend had found a website for Charon Stichting. ‘It’s a charitable health foundation. Stichting just means “foundation”,’ the research intelligence officer said.

The detective chief inspector looked through the English-language version of the website. It was glossy and professional, with many photographs of trustworthy-looking white-coated male medics. They all had perfect smiles and good hair, stethoscopes resting over their shoulders, often conferring with gorgeous but studious female researchers at their microscopes in pristine and modern-looking labs. It wasn’t immediately apparent what specific services Charon undertook; if he had not read the text, Gillard would have assumed it was some Florida cosmetic surgery outfit. After five minutes of skimming, looking past the euphemisms and corporate-speak, it was clear to him that the organisation was involved in end-of-life care. Helping afflicted individuals make difficult choices and guiding them on their chosen paths. Much was made of the charitable end of the organisation, in which those with incurable diseases and limited means were, in one memorable phrase, ‘offered pain-free off-ramps from the highway of suffering.’ Buried within the website was a section with its own email address that offered to connect those wanting ‘bespoke services’ with others willing to provide them.