Raiders of the universes

An astronomer named Phobar employs an experimental device, Mercia's nullifier, to observe a sequence of new stars appearing in a straight line and advancing toward the solar system; each manifests as a rapidly moving sun and an eighth erupts alarmingly close. Further observations reveal a dark, planet-sized invader linked to a blazing filament that strips and reheats Neptune and throws planets out of their orbits. Scientists grapple with the mysterious force and whether intelligence guides the phenomenon as astronomical discoveries escalate and the solar system faces potential disintegration, while global authorities and observers confront mounting fear and uncertainty.