“Poor Castro?” I said, staring at the images with a foul taste in my mouth.
“Dr. Lucas Castro,” Cardoso said. “He was the first in the world to diagnose Hydra. He saw a four-headed version in the upper Amazon when he was working for the World Health Organization. He was also the doctor who diagnosed the six-headed cases two years ago. Those two children and Dijon.”
“We were there, Tavia and me,” I said. “Didn’t he want to quarantine one of the favelas?”
Dr. Cardoso nodded. “Castro feared that the outbreaks weren’t over, that Hydra would return stronger and deadlier than ever. And no one listened. He got so upset about it, he quit his job at the Oswaldo Cruz Institute because no one there took his warning or his work seriously.”
“I remember him,” General da Silva said. “Where does he work now?”
“Here,” Cardoso said. “Upstairs. I’ve been waiting for your permission to show these images to him.”
General da Silva chewed on that a moment before saying, “Can’t stick my head in the sand. Let’s get Dr. Castro involved pronto.”
We arrived at Dr. Castro’s door a few moments later. Brazilian dance music played inside. The medical examiner knocked sharply.
“Yes, yes, just a moment,” a man’s voice called out, and the music was turned off. The door opened.
Tall, bearded, late thirties. The man’s eyes flitted over us. “Can I help you?”
“Dr. Castro?” General da Silva said, and he identified himself as the chief of Olympic security. “We have something you need to see.”
“Oh?”
“You discovered Hydra?” I asked.
A cloud came over the doctor’s face. “If that’s what this is about, I’d rather not discuss it. No one was interested after the last outbreak, so I—”
Castro stopped, gazed around at us, said, “Has it surfaced again?”
“A mutation of it,” Dr. Cardoso said. “We’d like you to take a look at a tissue sample, tell us for sure.”
“Now someone’s going to listen to me?” Castro said bitterly. “Now you want my help?”
“Better late than never,” the medical examiner said.
The doctor thought about that and then sighed. “Of course. Let me look. Where are these samples?”
“Down in pathology.”
“Right here in Hospital Geral?” Castro said, surprised, as he finished locking his office door. “I hope to God safety measures have been taken.”
“The tissue was recovered from a badly burned body,” Dr. Cardoso said. “The heat would have killed any remaining live virus.”
Dr. Castro relaxed, said, “If it was hot enough, that’s right.”
As we walked back to the pathology lab, we filled Castro in on Luna Santos and the discovery of her burned corpse.
“Barra da Tijuca?” he said. “That’s far from the favelas.”
“What’s the significance?” da Silva said.
Castro said, “The outbreaks have always come in small clusters in dense populations, people living all over each other. Even in the early outbreak in the Amazon, the victims all lived within yards of one another in the jungle. So my thinking is, why does someone like this Luna and not one of the favela people get infected? And how? And are there others?”
Tavia said, “For all we know, Doctor, she visited a favela and came in contact with someone carrying the virus.”
Dr. Cardoso said, “In that scenario, at least two people have been exposed to Hydra in Rio in the past few days.”
“Yes, if your victim contracted Hydra from another human,” Castro said as we reentered the pathology department. “But, you see, that’s been the mystery with the disease right from the start. Where did it originate? Some filthy backwater of the Amazon? From a tick on a rat or a monkey? Or in bird shit? And how does it travel now? Airborne? Blood to blood?”
“Level with me, Doc,” General da Silva said. “How contagious is it?”
“We don’t know,” Castro said. “The first outbreak in the jungle was controllable, occurring in a place where it could be surrounded and burned out. But the last time, do you remember? During the World Cup?”
“We were with Henri Dijon when he collapsed,” I said.
Dr. Castro seemed impressed, said, “You’re both lucky to be alive. Did you have symptoms?”
“No.”
“Interesting. Strong constitutions. Extraordinary immune systems.”
Tavia said, “I’m puzzled. Why weren’t you brought in to help us two years ago, Doctor? You’d diagnosed the earlier cases. You were the only one who’d ever seen it firsthand.”
The doctor’s face clouded. “This is what happens when politics control science, Ms. Reynaldo. Because I challenged an idiot who worked for the mayor, because I argued for a quarantine of the favela where the children were infected, I was persona non grata.