Instinctively the crowd drew back, terrified by this renewed proof of the malignant power possessed by this killing floor. The screaming redoubled in volume as those at the back were toppled and trodden underfoot. As the attendants ran to try and contain the crowd, Grimaldi stood up, his blue suit stained with the blood on which he had slipped. It was almost invisible on the marble slabs, a light spattering that blended perfectly with the scarlet veins beneath the highly polished surface of the stone.

He retrieved his radio and pressed the call-up button. While Control took their sweet time about answering, as usual, Grimaldi looked round to try and find the man in the suede jacket and the woman in the tweed coat, but they were no longer there.

‘Well?’ a crackly voice demanded crossly in his ear.

‘This is Grimaldi. We have a jumper in the basilica.’

‘In progress or complete?’

‘Complete.’

He switched off the radio. There was no need to say more. Suicides were a regular occurrence in St Peter’s, partly due to the vertiginous attraction of high places in general, but still more to a popular belief that those who died on the Apostle’s tomb went straight to heaven, by-passing the normal red tape and entry quotas. The Church had preached repeatedly and at length against this primitive superstition, but in vain. The part of the inner gallery beneath the dome that was open to the public had been fitted with a two-metre-high wire-mesh security fence, but if folk want to kill themselves badly enough it’s impossible to prevent them doing so.

Nevertheless, this particular jump was unique, at least in Grimaldi’s experience. As far as he knew, no one had ever managed to commit suicide while Mass was being said, for at such times there was no access to the dome.

Grimaldi’s message set in motion a well-established routine.