“So what did I miss?” Nefret said as she took a sandwich from the platter. “Did you make any progress with the serdab, Professor?”

“Not as much as I would have if that blasted Morgenstern had not appeared,” growled Emerson. “The workmen are still angry with him, and they would have caused an uproar had the missionary fellow not dragged him away from the site. None of us could understand his gibberish. How did he escape from the dahabeeyah?”

I studied a sliced egg sandwich while I considered how best to explain without further upsetting him. “He told Fatima that he was leaving and went to the dig house. I found him there. He was lucid when I arrived, but began to deteriorate rapidly. I was unable to detain him. I assumed that you could do whatever was necessary, Emerson, so I searched the dig house and returned to the dahabeeyah to think.”

“I may be able to help explain his behavior,” Nefret volunteered. “While Liezel and I sat on a bench at the police station, waiting interminably for someone from the German embassy to send a telegram authorizing her to have the body transported to Cairo, I asked about her research. She and von Raubritter were experimenting with a drug that has a complicated formula but is commonly known as MDMA. Merck, a pharmaceutical company located in Darmstadt, has applied for a patent, despite the fact that the drug has no acceptable medical or therapeutic applications. It can, however, produce grave side effects. Many of the lab animals displayed confusion, memory loss, and psychosis.”

Emerson laughed. “Did these lab animals submit to psychoanalysis? Did they forget their names and addresses?”

“They dashed themselves against the bars of their cages,” Nefret replied stiffly, “and were unable to navigate a familiar maze that led to food. Morgenstern has exhibited many of the symptoms. Liezel could not explain how he might have received doses of MDMA. Surely he would not have taken it voluntarily.”

I put down my teacup. “Liezel told me earlier that the laboratory was visited by German military officers, ambassadors, and assorted aides. One of them might have stolen some vials of it.”

“You suspect the German ambassador to Egypt?” Emerson scoffed. He can be quite sarcastic when he is in the grips of impatience. It is a reaction that I have almost given up attempting to mellow over the years.

“Well, no,” I was obliged to respond, “and even if he were the culprit, how could he have dosed Morgenstern on so many occasions? The only constant in Morgenstern’s life is schnapps. When I first encountered him this morning, he was rational but kept gulping from a bottle on the counter. He has a case of the vile stuff in the storeroom.”

“Someone might have tampered with the bottles,” said Nefret, abruptly putting her teacup aside.