After seven days of investigation, research, and discussion, human civilization and eleven Silver Species civilizations unanimously confirmed that all life in that star system had not perished from a material-level attack or the natural environment.
No cause of death could be found from any material perspective, including from physical, biological, radiological, energy, spacetime curvature, or any conceivable material manner of death.
Crucially, this type of death unfolded over the size of an entire star system. Within such an expansive area, every planet, asteroid, meteor, space station, spaceport, and large cosmic manufacturing factory—all with different environments and vastly separated—had all died at the same time.
So the final conclusion was... this death could only originate from a consciousness level, an information level, or the Dark Matter level.
"... There is no such weapon!"
