Tenebrae was a strange entity from a another Universe. She was a member of a larger race known as the Mergence, whose goal was the absorption of the planet Earth. Her plan included manipulating the Silver Surfer as her ultimate weapon for the absorption to take place. Tenebrae had convinced a human known as the Coroner to join her and betray his race. It was through the Coroner's mind that the Mergence had been summoned from across the stars to the Earth. Her plan encountered flaws that led her to the sub-universe, called the Microverse, where she convinced the Psycho-Man to join her cause.
With the help of her new ally Psycho-Man, she defeated the Silver Surfer. Together they managed to breach the zone between Sub-Atomica and Earth to begin their conquest. Arriving on Earth, She found her ally Cy-phyrr 4 awaiting her, with something far more sinister looming in the balance. The trio was ambushed by the Mergence, who had taken possession of the Coroner's body, mutating it into a deadly vessel of destruction. With the Surfer unconscious, the destruction of the world appeared inevitable.
The Mergence sought to kill Tenebrae for choosing individuality over the collective consciousness of her race. Tenebreae pleaded for her life but her plea was not honored due to her taint of singularity. With the help of Psycho-Man, it appeared that she was able to escape with her life.