This blunt challenge knocked Y'ang-Yeovil off balance. He knew that the crux of the "Nomad" situation was the presence on board the ship of 20 pounds of PyrE, the total world supply, which was probably irreplaceable now that its discoverer had disappeared. He knew that Sheffield knew that they both knew this. He had assumed that Sheffield would prefer to keep PyrE unnamed. And yet, here was the challenge to name the unnamable.