As was expected, the failure of the entire traffic system led to widespread chaos across Mumbai. The immediate result was hundreds of accidents, some small, some serious, some critical. The number of casualties was still mounting as Vikrant sat in the back seat of a police SUV he had commandeered from the LT Marg Police Station. A constable from his team was driving him.

Because of the traffic jams on almost every road, it was impossible for ambulances to reach the scene of any casualty. Ambulance nurses started running on foot with stretchers on their shoulders, loading the nearest casualties on them and running back to the hospitals. Citizens started volunteering as the trend caught on, and stretchers were passed from shoulder to shoulder in cases where the injuries were not too serious.

Hospitals found themselves overloaded with accident victims. Reports of at least twelve deaths in various parts of the city were heard on the police wireless that Vikrant was carrying, now switched on, and the toll was expected to mount. Many of the less seriously injured were treated in makeshift wards in the hospital compounds and released as soon as possible so that the doctors could deal with the more seriously hurt.

Private practitioners started accepting those injured in the traffic snarls on priority, requesting other patients to wait if they could do so. As soon as Vikrant heard of one such report, he called up his office.

“Tell the Mumbai Police to tweet about this so that other doctors may see and follow suit,” he told his team, which was constantly scanning social media sites and relaying updates to the Mumbai Police team.

Social media was one tool whose power Vikrant was increasingly becoming aware of. It was an invention that could be as good, or as bad, as the person using it.

Traffic policemen and wardens started working in collaboration with citizens’ associations and soon, hundreds of volunteers came out on the roads to help move as many vehicles as possible. The Traffic Police chief had a sudden brainwave and issued an order, which Vikrant heard on the wireless and marvelled at.

“Push all two-wheelers onto the pavements and forbid their riders from moving until the bigger vehicles are cleared off the roads first. Put clamps on the wheels if you have to. Arrest anyone who acts over smart.”

Two-wheelers have, since forever, been the biggest bane of a traffic policeman’s life. The highest number of road accidents every year are caused due to rash two-wheeler drivers trying to beat the signal at a busy intersection or overtake a heavy vehicle from the wrong side. The tendency of these riders to ram their vehicles into every inch of available space has been the cause of many a traffic jam.

Vikrant’s phone rang just as his vehicle got on to the JJ Flyover. It was packed but at least the traffic was moving. Vikrant silently thanked whoever came up with the idea of banning two-wheelers on the flyover. He shuddered to think what the situation might have been today had the ban not been put into place.

“We’ve wrapped up the operation over here, sir,” Deo said from the other end.

“Leave the accused at the LT Marg lockup for today. Have them take the injured one to the hospital. Don’t want him causing any trouble over it later,” Vikrant instructed his junior.

“Already told them that, sir,” Deo said, his voice betraying the touch of joy that a teacher’s pet feels when he gets the answer right.

“Good man,” Vikrant said. “Get to the office ASAP. There’s something I might need your help with.”

Vikrant sensed the smallest of pauses at the other end, during which he guessed his junior was debating whether or not to ask any questions.

“I’m leaving right away, sir. I’ll send you a text when I get to the office,” Deo ultimately said.

Vikrant could feel his approval for the man increasing as he went back to monitoring the chaos around him on his wireless. The Mumbai police commissioner, very reluctantly, issued prohibitory orders, restricting movement on the roads unless absolutely necessary. People were instructed to stay indoors wherever they were, be it at their homes or workplaces, and city police personnel were ordered to assist their traffic police counterparts in whatever way they needed. All personnel with special units, like the Crime Branch, who were not working on anything urgent at the moment, were also ordered to help out.

Small businesses took a hit, as there was no possibility of customers coming in on a day like this. The stock market fell by several points, leading to panic on the economic front.

Vikrant was particularly concerned because the Indian economy was anyway making a slow recovery after going through several upheavals including communal strife, border escalations and sporadic terror incidents, not to mention a series of natural disasters. If what Mirza had just sent him was true – and Vikant had no reason to believe otherwise—he was afraid that the market would plummet badly and take a long time to come back to normal.

There were occasions when the Sensex had opened in the red zone of 0.09 per cent margin and although it had recovered through the day, that was enough to cause massive financial losses to the business community. There were also times when it had opened at a dismal 0.07 per cent and later corrected itself. But what Vikrant was actually worried about was a panic-induced selling spree, which always causes catastrophic losses.

The news media, of course, was agog, with reporters descending on the roads and accosting everyone, be it civilians or officials.

There was hardly anything that could be done to stop them, as they were fully within their rights in reporting such a massive ongoing crisis. There were, of course, some unruly journalists too who were disrupting the police’s efforts to deal with the situation, but it was a pain that would have to be borne.

In the midst of all the chaos around him, as his vehicle slowly inched towards Nagpada, Vikrant reread the email that Mirza had forwarded him on the messaging app. He had read it twice already but was still trying to believe what it said.

What you are experiencing right now is called a Distributed Denial of Service or DDoS attack. I’m sure you have experts who will break it down for you in simple terms, but what I have basically done is caused the server that controls your traffic signals to crash.

As your experts will tell you, such an attack requires a massive number of hacked devices. I should warn you that the number of devices I used for this DDoS attack is only a fraction of what I have at my disposal. If my demands, which will be conveyed shortly, are not met, my next target will be an even bigger public utility.

Consider this a warning.

Excerpted with permission from Zero Day, S Hussain Zaidi, HarperCollins India.