“Three valves,” Elías whispered, his own heart racing. “A triplex lesion.”

The old man’s eyes fluttered open. He reached out a trembling hand and grasped Elías’s wrist. His pulse was weak, but regular.

“No echo tonight, no enzymes for an hour,” the night nurse whispered. “It’s just you and the old ways, doctor.”

First, the apex. Lub-dub . Then, a whisper. A murmur, soft as a moth’s wing, then roughening into a late-peaking crescendo. Click. Murmur. Click. A metallic taste in the sound. “Mitral valve prolapse with regurgitation,” he breathed. “But listen deeper.”