At that moment a flood of police officers burst out from under the curtain of the Cologne police float. Benni Scholz, who had been riding on top, leapt from the float, still dressed in his comedy police costume. The crowd cheered enthusiastically, thinking it was all part of the act until the officers barged into the crowds. Vitrenko looked down at Fabel, then at the knife in his gloved hand. He dropped it and ran, disappearing into the crowd.

‘Get after them!’ Scholz screamed at his men. He pushed through the crowd to where Fabel had fallen.

7.

Scholz put his arm around Fabel’s shoulders and gently eased him up.

‘You okay?’

Fabel looked down at his punctured coat and jacket. ‘Just winded.’

‘It’s a good job you were right about his weapon of choice. If he’d brought a gun that stab-vest wouldn’t have helped much.’

‘Let’s go,’ said Fabel.

The uniformed officers had already grabbed two of the masked men and pulled their masks from their faces. Fabel, Scholz and half a dozen uniformed officers pushed on through the crowd which thinned out the further they moved away from the procession.

‘There!’ shouted one of the uniforms and pointed to where a dark figure had cleared the crowd and ran off in the direction of the Rhine.

‘No … wait,’ shouted Scholz. ‘There’s another one.’ He pointed to a second figure, heading off towards the railway station. ‘And another …’ A third gold mask flashed in the winter sunlight as it turned in their direction before running towards the back of the cathedral.

‘We’ll have to split up and go after them all,’ shouted Fabel. ‘But a minimum of three men on each. These are dangerous bastards. Benni, we’ll take the cathedral guy. You armed?’

Benni reached deep into his oversized outfit and produced his SIG-Sauer automatic. He ordered one of the uniforms to come with him and Fabel and they sprinted off in the direction taken by the third masked man. They came round to the south side of the cathedral and suddenly they were alone. The cheering of the crowd was still loud but seemed to Fabel to belong to another universe. They stopped and caught their breath.

‘He can’t have got round the rear,’ said the uniformed cop. ‘He didn’t have time.’

Fabel strained his neck to look up at the immense looming mass of the cathedral. They were on the south side and a row of massive flying buttresses, each tipped with a spire, flanked the cathedral’s nave like a rank of soldiers. His eyes fell to street level and caught sight of a side door.

‘Is the cathedral open today?’ he asked.

‘Not to the public,’ said Scholz. ‘But there’s a special Fastenpredigt pre-Lent Mass later. They’re probably preparing for that.’