The year is 2029. A terrorist breeds black mambas and milks their venom and uses it as a deadly weapon. He loads it in horsefly looking robots which bite people during summer.
Before he loads the venom, he processes it, and it becomes 30 times more potent than usual. He sends an army of 205 horseflies during an unusually warm summer to exterminate and rake havoc.
The horsefly robots look like the indigenous insects, but they are quieter in fright with a painless sting. The horseflies are intelligent and can distinguish between friend and foe. They can stealthily enter into people's homes and deliver snake venom to unsuspecting family members.
They wait when people are asleep and deliver their deadly sting, killing people in their sleep. In one boarding school, ten robots kill fifty children in one night. They then invade a hospital and kill countless patients and doctors.
They hide during the day under beds, chairs, and desks and repeat their mission at night fall until they have emptied their toxic load. They fly back to the terrorist to recharge and refill and proceed to another hospital or school.
Tests show that people are dying of snake venom, but there are no snakes. Another perplexing phenomenon is the speed at which people die. Snake venom can kill a person within 12-48 hours depending on the amount of poison injected. However, with the robots, people die within a few hours of being bitten.
A deadly fear descends and spreads over all people. The doctors suspect a virus or a new disease that they don't understand. During the confusion, a doctor picks up a horsefly that has fallen on the floor after its battery malfunctions.
On examination, he concludes that it is not a normal horsefly, but a robot. When he tests the contents, it is snake venom in a refrigerated chamber. He alerts the authorities and investigations trace the horsefly robots to a terrorist network.
Police arrests the terrorists. The death toll from the attack is 61. The authorities declare three days of mourning for the dead. The local mayor warns about “the dangers of unregulated advances in artificial intelligence.”