They returned to the SCIF and within eight minutes Marie Lafont had a bio on Heidi Winnen, and a picture that she projected onto the SCIF’s screen from her laptop. ‘She’s a chemical engineer, with a company called Rotterdam Associates. At university she had a boyfriend called Nasim ul-Huq, a Pakistani science student who was heavily involved in PLO politics.’

‘Heidi was radicalised?’ asked Briffaut.

‘Doesn’t say,’ said Lafont. ‘She’s worked all over the world in major water infrastructure engineering and now she seems to be in charge of Rotterdam’s pitch into water utilities in France, Germany and Spain. The best part? Nasim ul-Huq—her boyfriend from university—is the owner of Rotterdam Associates. It’s in Paris.’

‘Is Nasim also known as Murad?’

‘We’re getting a photo.’

De Payns asked, ‘What is Rotterdam selling?’

‘They install new chemical water filters. It’s called chloramine disinfection.’

‘Chloramine? Not chlorine?’

Lafont read out what was in front of her. ‘It says chlorine and ammonia, the latest way to ensure clean water. It’s the final part of the water treatment process. There’s a link here to a media release. They’re installing the biggest system in Europe this week.’

‘Where’s the installation?’ asked de Payns.

‘Saint-Cloud,’ said Lafont.

‘Saint-Cloud treatment plant? That’s in Paris,’ said de Payns.

Frasier reached for the landline and punched the DGSI number.

‘Claude,’ he barked. ‘That shit I briefed you on? It’s Saint-Cloud—they’re targeting Saint-Cloud.’ There was a pause. ‘Yes, the fucking Paris water supply!’ Another pause. ‘Okay. Stay on the line.’

Frasier hit mute and looked around. ‘Malle wants me to contact Saint-Cloud—he’ll join the call. Someone get me the CEO.’

Saint-Cloud was one of six drinking-water plants owned by the City of Paris and its water company, Eau de Paris. It drew water from springs as far afield as Normandy and Burgundy, continuing a tradition of transporting water into the city by aqueduct that had begun a little more than four hundred years earlier, under the Medicis.

Lafont scrolled through her phone and called a number at the DGSE, and then leaned over, ‘hung’ the Malle call, and dialled in another number. They got the head of operations—Jean-Pierre Thorens—after waiting seven minutes, and explained the situation.

‘Claude Malle, DGSI, and Anthony Frasier, from the government,’ said Malle to Thorens, who wasn’t concerned.

‘Our infrastructure security exceeds the EU requirements and the Americans even tour here to see what we do,’ he said haughtily. ‘We are Paris’s water supply. It’s serious infrastructure with a national security designation, Monsieur Frasier.’

‘I don’t doubt it,’ said Briffaut, jumping in. ‘It’s just there could be a saboteur in the engineering firm Rotterdam Associates. They’re installing new chloramine filters this week?’

‘Today, actually,’ said Thorens.