'I think there's no question of that. But it's academic; I'm told there's almost no chance of the submarine being found, in those conditions.'

'Wouldn't the crew have signalled by radio if the ship had been in some kind of distress?'

'If they could have surfaced to do it, yes. They might not have been able to do that.'

'Do you think it was a depth charge — a warning depth charge the Soviets had in fact dropped but later decided to deny — that sank the submarine?'

Two or three of them looked at the thin man who sat with his legs crossed, tall in the chair. I put him down as Admiralty. 'It would need a great number of depth charges to sink a vessel the size of the SSN Cetacea. Again, the Soviets could have dropped a very great number, without coming anywhere near the target. The boat would have normally surfaced perhaps a couple of times a day to spread her antenna and signal base; in those waters, where in midwinter there's no sunlight at noon, she could have done this quite close to the Russian coast without being seen. In other words, I don't think for a moment that she was unaware of her location at any time; and if the captain had heard one depth charge going off, he would have surfaced — or changed course at once towards the open sea.'

'Can we be sure that the Soviets did in fact detect the presence of the Cetacea off their shores?' The PM.

'Not completely sure, ma'am.' He recrossed his long thin legs. 'But it would have been difficult for them not to. In those waters, very close to their largest naval base at Murmansk, they have underwater listening stations in a very wide array. Transonar-transducers would pick up the presence of an alien vessel easily enough, and relay the information to manned posts. Of the Soviet's six hundred or so active submarines, about four hundred are obsolescent diesel-powered boats used for patrolling the shores of the entire continent of Asia. A good few of these patrol the Barents Sea, to protect Murmansk, and they could well have picked up the noise of the Cetacea. They would-'