The world of Orbucen was at its end when the world devourer, Galactus, prepared to feed on it. Harrow added to the fear and chaos of the inhabitants while they fled for safety by seeking hapless individuals to victimize. First, the mind a young boy was infiltrated, and the small child acted out Harrow's murderous wishes. Then a security guard who killed the small boy was manipulated by the evil entity. Sixty-four corpses later, Harrow was discovered by Nova who was planet side, hoping to facilitate the evacuation. During a brief struggle, Nova caged Harrow while his mind was occupying one of the natives of Orbucen. However, Harrow figured out how to escape his prison and adapt to Nova's power while Nova was fighting the Silver Surfer. When Nova returned to the planet, he was even more determined to catch the killer, but during his second attempt to stop Harrow, Nova was caught in the ignition blast from an escaping ship leaving him near death. Worldmind assumed Harrow was destroyed in the blast.
Nova needed to get off the planet before Galactus completely drained it of its energies, so he found a way to get on board the world devourer's ship. Once there, his suit's computer detected Harrow's presence, and Nova set out to finish what he started on Orbucen. He found Harrow hibernating in the bowels of the space ship, but once Nova decided to attack, Harrow awakened and brought the fight to him first. Harrow entered Nova's mind, and that's when Nova found out how long Harrow has existed. Nova also exposed the secret of how long Harrow had been traveling with the world devourer – since the trial of Galactus. Harrow had stayed hidden from Galactus within his Cone of Psilence, a potent psychic shield that even the most powerful minds cannot detect. Harrow was using Galactus to feed on the terror of each of the worlds he annihilates. Nova became enraged at how much worse Harrow makes it by preying on those already struggling to survive. Nova engaged the ageless entity, and the two fought furiously on the space vessel until the Silver Surfer interrupted them. The Surfer read Harrow's mind and was disgusted by the creature's intentions. The Silver Surfer used his Power Cosmic to shatter Harrow's Cone of Psilence, and as the parasite tried to escape, Galactus incinerated him.