Rakesh Sharma, a senior Kashmir police officer who had run several counter-terror operations against Pakistani terror outfits active in the Valley, most of them in collaboration with the CTC, got in touch with Shekhar.

It was around 11.30 p.m. on 30 August 2008 when Shekhar got a call from Rakesh.

‘How are you, sir?’

‘Hello, Sharma, I’m fine, thanks. It’s good to hear from you. Tell me, what is new?’

‘A covert intelligence operative of ours, “Mongoose”, who is embedded in the LeT, got a valuable scrap of information. A local LeT commander asked him to procure thirty-five Indian prepaid SIM cards, but not from Kashmir. They will be sent to Pakistan via special human couriers.’

‘This is valuable intelligence,’ Shekhar said. ‘Mongoose is a great find, a real talent. I want to make the most of this opportunity. I want to send some of my own SIMs in the lot that will go to LeT in Pakistan.’ Shekhar couldn’t believe his luck.

‘Yes, sir. That is exactly why I called you.’

‘I will send you three SIMs from Delhi. LeT might use them if and when an attack is launched in India.’

‘Yes, sir. Please send the SIMs, and I will ensure they get to LeT.’

Shekhar’s aide bought the three SIM cards, using fake identity particulars, from a SIM retailer in Delhi. The SIM cards were sent to Mongoose in Kashmir through covert channels.

It was one of the three SIM cards, number 91-99107194XY, which became active around 9.50 p.m., three months later, on 26 November 2008, when LeT’s ten-man fidayeen squad, including Ajmal Amir Kasab, took the 550-nautical-mile-long sea route from Karachi’s Keti Bunder creek to land at Mumbai’s Budhwar Park seashore at Cuffe Parade.

The SIM was being used by one of the ten fidayeen. Till then, the three numbers had been dormant.

Over the next fifty-nine hours, the Pakistani Lashkar terrorists, who were armed with AK-47s, RDX-based eight-kilo bombs, and grenades, attacked five iconic spots in Mumbai: the Taj Mahal Hotel, the Oberoi–Trident Hotel, Leopold Bar and Café, Chhatrapati Shivaji Terminus and the Jewish Chabad.

The intercepted number gave the first breakthrough in listening in to the real-time commands being relayed to the Mumbai attackers by their Karachi-based command centre, manned by senior commanders including Abu-Lakhvi, Abu-Muzammil, Umar-Qama, Sajid Mir alias Wassi and Hamza.

At 1.26 a.m. the same night, the conversations that were tapped into yielded a lead that proved crucial in analysing the nature and source of the attacks.

Controller (C): Are you setting the fire or not?

Mumbai attacker (MA): Not yet. I am getting a mattress ready for burning.

C: What did you do with the body?

MA: Left it behind in the boat.

C: Did you not open the locks for the water below?

MA: No, we did not open the locks. We left in a hurry. We made a big mistake.

C: What big mistake?