At 10.45 a.m. we were ready to roll. Our CO and ops officer were installed alongside the police in a control room set up in Marylebone police station. I knew that at the last minute, before we went in, the CO would take command of the operation by signing the formal order, but that didn’t concern us at the sharp end.

The police team who had Markham Court under surveillance confirmed that nobody had entered or left No. 10 since the arrival of Barrakuda, so we were reasonably confident that we’d find only two men inside.

Red team slipped into the building so easily that we might have been arriving for Sunday morning coffee.

Just as we were debussing a small, heavily veiled Arab woman came out of the block. Funny, I thought, she’s just like us, dressed in black from head to foot. She did a big double-take at the sight of us. I thought she was going to dart back inside, but she kept going and walked off along the street.

One of our lads got a foot in the open door, saving us the need to pick or smash the security lock. Then it was three into the lift, two running up the stairs, and the sixth man staying down to guard the entrance.

Outside No 10. I paused till I heard from the commentary in my earpiece that Blue team were in position at the head of the fire-escape. Then I quietly said, ‘Placing charge now.’ The door had a peep-hole in the centre at head level, but as we’d arrived in total silence the chances that anyone was standing with his eye glued to it seemed exceedingly remote – so I ignored it and went forward to tape the det cord straight down the middle.

With that done, I stood back against the wall, the other guys lined up beyond me.

‘Red, all set,’ I reported.

‘Blue, ready,’ came the answer.

‘OK then. Stand by . . . stand by . . . GO!’

I closed my clacker. The bang was very sharp and loud in the confines of the little landing, and the front door split in half and caved inwards. I lobbed a stun grenade through the opening, squinted sideways as it cracked off, and burst into the flat.

Two men in shirtsleeves were sitting at a table – or rather, they had been. By the time I entered the room they were half-way to their feet, staggering backwards in shock from the explosions.

‘Stand still!’ I yelled. ‘Hands up!’

I saw immediately that the left-hand man was Barrakuda: a smaller version of Akula, with the same hollow cheeks, but younger, maybe in his late thirties, his features less haggard. He’d been taken completely by surprise. Before he could move two of our guys had him pinioned and cuffed with his hands behind his back. His companion was a big fellow, older and heavier, with stiff brown hair brushed up and back. He, too, was instantly overpowered.