“Our bodies are amazing inventions. It almost makes you believe in God.” Decameron paused. “Almost. We have a wonderful invention called the immune system. It recognizes the Huns out there, the invaders of our bodies, and wipes them out. Any foreign substance—a virus, a bacterium, a cancer cell—will eventually be discovered as an interloper and destroyed if one has a properly functioning immune system. A very good thing. Without it, we’d all take the route of AIDS patients.”

Decameron looked at Oliver.

“Okay, so far,” Oliver said. “Go on.”

“Well, sometimes you can have too much of a good thing. Sometimes the immune system is overactive. For most of us, if we get an irritant up our noses or get a bee bite, we might sneeze a bit…or swell up locally. But eventually everything settles down. A few unlucky souls have immune systems that overreact—send out droves of histamines to fight off a little interference. Cellular walls break down, fluid is poured into the tissues, and the body swells up.”

“An allergic reaction,” Marge said.

“Exactly,” Decameron said. “The most dangerous sequela of an allergic reaction is in the lungs. The breathing apparatus can become so inflamed that often air can’t pass through.”

“So what does this have to do with Curedon?” Marge asked. “It prevents an allergic reaction?”

Decameron nodded. “In a sense, that’s what it does. When a heart is transplanted into a body, the body’s in-place immune system doesn’t recognize the heart as a necessary part of the body. It sees it as a foreign substance, and sends out white cells to destroy it.”

Oliver said, “So it’s like the patient has an allergic reaction to his or her new heart.”

“Essentially, yes,” Decameron said. “Without proper medication, the immune system would eventually eat the heart away.”

Marge said, “I thought that transplant patients are tested to make sure there’s a fit between the new heart and the old body.”

“Of course, we type-match, Detective. We do the best we can. But often it isn’t enough. There’s a sad shortage of hearts and lots of people with heart disease. We have to make do. That being the case, we have to work around the immune system. We have to undermine it. Hence, the class of drugs known as immunosuppressants. Cortisone for example.”

“You give heart transplant patients cortisone?”

“No, but surgeons give them related immunosuppressants. Like prednisone. The most commonly used drugs are Imuran and Cyclosporin-A. With severely compromised renal patients, surgeons often use the more experimental class of immunosuppressants—Orthoclone or OKT3—and the other Ks like FK506. Sorry to bore you with details, but it will help you understand the importance of Curedon.”

The room fell quiet. Marge wrote as fast as she could.