She rolled a third between thumb and forefinger, as if she might decide to smoke it. "Tungsten," she said, "and rhenium. Alloyed, they’re superheavy." She sighted along the dart’s black tip, almost invisible in this light. The heavy, multilayered drapes were drawn against the night, and only the tiny, focused, supernally brilliant Swiss bulbs, in the birdcage library, lit the room and its artifacts. "Place Ajay knows. Cost a hundred pounds apiece. You want to make supersonic shrapnel, you make it with this stuff."