Dr. Vaseegaran has recently built a new android humanoid assistant named Nila, whom he introduces to a group of college students. Shortly after, all the mobile phones in the city begin to fly into the sky, throwing the public into a panic. A scientific council assembles to discuss the phenomenon, in which Vaseegaran suggests reactivating the robot Chitti. But the plan is opposed by a member of the council, Dhinendra Bohra, whose father was killed by Chitti a few years back.
The cell phones gather into a swarm and kill phone retail store owner Jayanth Kumar, telecom company owner Manoj Lula, and Telecom Minister Vaira Moorthy. The Home Minister S. Vijay Kumar gives permission for Vaseegaran to reactivate Chitti, whom he has already started working on. The cell phone swarm destroys phone towers around the city and wreaks havoc on the public, manifesting as a giant bird. A newly activated and upgraded Chitti battles the bird in the city and destroys it with an explosion. The remaining phones retreat and reform. Chitti, who runs out of battery takes refuge in three antennas at a space station. The bird tries to follow but is repelled by the antennas.
Chitti informs Vaseegaran about this incident and confirms that the phones are powered by an aura, specifically a concentrated mass of negative charge with electromagnetic properties. Since the space station was streaming positive charged ions into space, the bird was repelled. Vaseegaran builds a photon synthesizer that projects positive charge, intending to neutralise the charge of the bird. The group confronts the bird and drains it of power. The phones take up a humanoid form, as the deceased ornithologist Pakshi Rajan.