Hemmed in by rusting Dogans and Sahins, Ali deftly manoeuvred his boss’s olive BMW up the steep slipperiness of Suleiman Caddesi. The snail’s pace soon slowed to a mechanical rigor mortis.

Aslan pondered the scene. A traffic jam is a perfectly democratic phenomenon, he thought. When the wheels stop moving, everyone’s equal.

He cleared some condensation from the rear window. If Ümraniye was soulless, Kartal was pure carrion: grey commercial blocks stripped to the bone. The occasional swathe of faded pink-and-yellow tiling, intended to subdue the monotony, became itself monotonous: lined up above the drab shop fronts like so many rotten teeth.

Down came the rain, blurring everything.

‘It’s the wipers, sir.’

Aslan looked up from Ali’s briefing document on the previous night’s events, spread across his knees. ‘Wipers, Ali? Is that what they’re calling terrorists these days?’

‘No, sir. These old cars. Their wipers can’t deal with the rain. That’s why people are always late in Istanbul.’

Aslan shook his head at Ali’s perennial genius for stating the obvious.

‘Was it raining last night, Ali?’

‘Belting down, sir.’

‘Deduction?’

‘Sir?’

‘Well, Corporal Ali, those guys who hit the Association of the Grand Temple of Free and Accepted Masons of Turkey must have arrived late.’

‘I don’t understand, sir.’

‘Most of the Freemasons had left by the time the shooting started.’

‘Amateurs, sir. Hitching a ride on the al-Qaeda bandwagon.’

‘Paid to think, are you, Corporal?’

‘Forgive me, Colonel.’

‘Not at all. You think away. Many a fool taught his teacher a lesson.’

‘If you say so, sir.’

‘Don’t you read your Rumi?’

‘Sir?’

‘Our great mystic poet, Jalaluddin Rumi.’

‘Not since he gave up football, sir.’

Aslan laughed. ‘Your first goal of the day, Ali. Well done.’

‘We’re nearly there, Colonel.’

Through the rain engulfing the BMW’s big windscreen, Aslan could just see lines of policemen in their soaked blue jackets directing traffic away from the site of the atrocity. A CNN Turkey News transit van was obscured behind a pack of foreign photographers, TV cameramen, producers and journalists, many of them pleading with the young policemen. The policemen nervously fingered their pistol holsters.

Behind the excited throng, exhibiting their customary patience in the face of officialdom, waited the more familiar faces of news-hacks from Hürriyet, Milliyet and Sabah – Turkey’s mass circulation dailies.

Ali slammed on the brakes and Aslan lurched forwards, his broad forehead hitting the back of the driver’s seat.

‘Arsehole!’ Ali tore into the driver who’d skidded close to the BMW, trying to avoid a gas cylinder truck.

‘Easy, easy,’ counselled Aslan to his unnerved driver. ‘It’s only a gas truck. You can’t go thirty metres in this city without one of these crawlers climbing up your arse.’

A fist banged on the nearside window of the BMW. Aslan instinctively reached for his Beretta, holstered to his left shin, then recognised the anxious face of Celik leaning out of the adjacent Merc. ‘Celik! How many atrocities do you want in twenty-four hours?’ Aslan lowered his window.

‘Join us in my car, Colonel. I don’t want any more reporters on my back. Ever since we discussed joining the EU they think they can do what they like. We can enter from the side.’

‘The EU?’

‘Very amusing, Colonel.’ Ali stifled a laugh as he made eye contact with Aslan in the rear-view mirror.

‘Thank you, Ali. Now see to the car. And Ali—’

‘Sir?’

‘Stay with it till I call you.’

Ali began reversing the BMW.

‘Not now, Ali! Let me get out first!’

‘Can I help with the door, sir?’

‘Bugger the door, Ali! I’ll do it myself. Like everything else round here.’ Aslan heaved his big frame out of the BMW and squeezed into the back seat of Celik’s Merc.

Celik was chewing an outsize thumbnail; his bloodshot eyes avoided Aslan’s stare. ‘Thank you, Colonel. Make yourself comfortable.’

‘You were right to call me.’

‘You know I’d never do anything without informing the NSC.’

‘I’m not the National Security Council, Celik. Just the liaison department. And where would you be without us, eh?’

Celik gave a half smile. It was a good job he was a flexible thinker, as the complexities of the Turkish justice system were mind-boggling. His loyalties were split between the city governor, Muammar Güler; the head of the moderately Islamic Justice and Development Party – the AKP – Recep Tayip Erdogan; and the vehemently secular army. And of course there was always the chaotic court of public opinion to answer to as well. It was a lot of pressure to bear, even for Celik’s broad shoulders.

Celik buttoned up his grey British Gannex raincoat and ushered Aslan out of his car and into a side alley, away from the klaxons and the rain. He tried to think of something ingratiating to say to the roughly dressed colonel. He wanted to say how much like Turkish movie heartthrob Cüneyt Arkin Aslan looked, with his slicked-back mane and tanned, ready-for-action features, but Celik doubted the compliment would have much effect. There was something annoying about Aslan. Whatever it was, it marked him out from the usual egotists, place-men and slippery smilers who populated the government. Aslan was neither easily flattered nor easily impressed. But was it modesty – or conceit?

Celik pushed the stainless-steel bar of a fire-exit door.

‘Where’s the light, Chief?’

Celik fumbled for the switch. Aslan heard it click, but no light appeared. The men edged forward, touching the cold concrete walls of the service corridor. Aslan felt glass crunch beneath his shoes. ‘So much for the bulb.’

‘The blast, Colonel.’

‘Possibly.’

As they rounded a corner, the men’s breathing eased. In the darkness, they could just make out a dull, door-shaped halo. Aslan gave it a hard kick. Swinging wide, the exit bar rattling in its own echo, the steel proscenium revealed a horrible scene.