The DGSE forensics team found traces of it on the brass doorknob of the château. It could be inhaled or ingested or absorbed through the skin. It was odorless and slow to deteriorate. It acted by blocking the messages from the nerves to the muscles, causing a collapse of bodily functions, and when given in large enough doses, it could cause lasting nerve damage, permanent disablement, or death. The substance would not wear off the surfaces where it was applied, so the DGSE anti-poison team had had to remove the brass doorknob where it had been applied and it would have to be replaced. It couldn’t be decontaminated.

Guy Thomas called Mike with all their findings at one a.m., which was seven p.m. in New York. Mike had been worried sick about Theo all day, but at least he knew she was in good hands.

“How is she?” he asked with deep concern in his voice.

“I think she and the bodyguard are feeling slightly better. Our friend at MI6 recommended the right substances to arrest the action of the poison and provide the antidote. The atropine stops the effects, and the oximes will counter it. Apparently confusion and dizziness set in very quickly. It’s a fast-acting poison, but the effect is far less severe than other nerve agents used in Russia. They’re both going to be okay. They’ll be kept in the hospital for a week of observation. They were lucky it wasn’t worse.”

“Why would de Vaumont do that, if he did?”

“Apparently he wanted to help one of his clients buy the château. It’s worth a fortune and probably represents a huge commission to him. I think the intention may have been very subtle. If she thought that she was so upset when she went there to the point that she felt ill, she might sell to him more quickly, and at any price. It’s one way to close a deal, if it was him. I took a statement from her and the bodyguard myself, and they both mentioned that he was wearing gloves. He may have applied the poison to the doorknob himself, or someone else did. It could have been a very convincing tactic, if you hadn’t figured out immediately what it was.”

“Robert Richmond at MI6 had given me some of the information before and it rang a bell,” Mike said simply.

“The Russians use a lot of those nerve agents. They can be brutal. With the stronger ones like Novichok, most of the victims die, or are severely impaired for years or for life,” Guy said.

“I’ve read a lot about it lately in The New York Times. We haven’t seen any of that here,” Mike said, deeply troubled by what had happened.

“I think we should arrange a conference call between you, me, and Richmond this week,” Guy suggested.