Exoplanet WS 905613. The atmosphere is thick, laced with spores of significant commercial value, and difficult to breathe without preparation. More interesting are the large calcified structures distributed across the planet's marshes: they emit signals across an unexpectedly broad range of spectrums, and the Walking Simulator A Month Club research division wants to know if that property can be adapted for deep-space communication—particularly the problem of reaching tomb-ships operating in absolute-zero silence across distances that make normal transmission impractical.