‘Eight years,’ said Kvant.
Gunvald Larsson picked up a sheet of paper from the desk and studied it.
‘Can you read?’ he asked.
‘Oh yes,’ said Kristiansson, before Kvant could stop him.
‘Read, then.’
Gunvald Larsson pushed the sheet across the desk.
‘Do you understand what's written there? Or do I have to explain it?’
Kristiansson shook his head.
‘I'll explain gladly,’ Gunvald Larsson said. ‘That is a preliminary report from the investigation at the scene of the crime. It shows that two individuals with size eleven shoes have left behind them about one hundred footprints all over that damn bus, both on the upper and lower deck. Who do you think these two individuals can be?’
No answer.
‘To explain further, I can add that I spoke to an expert at the lab not long ago, and he said that the scene of the crime looked as if a herd of hippopotamuses had been trotting about there for hours. This expert considers it incredible that a herd of human beings, consisting of only two individuals, should be able to wipe out almost every trace so completely and in such a short time.’
Kvant began to lose his temper, and stared stonily at the man behind the desk.
‘Now it so happens that hippopotamuses and other animals don't usually go about armed,’ Gunvald Larsson went on in honeyed tones. ‘Nevertheless, someone fired a shot inside the bus with a 7.65 mm Walther-to be exact, up through the front stairs. The bullet ricocheted against the roof and was found embedded in the padding of one of the seats on the upper deck. Who do you think can have fired that shot?’
‘We did,’ Kristiansson said. ‘That's to say, I did.’
‘Oh, really? And what were you firing at?’
Kristiansson scratched his neck unhappily.
‘Nothing,’ he said.
‘It was a warning shot,’ Kvant said.
‘Intended for whom?’
‘We thought the murderer might still be in the bus and was hiding on the top deck,’ Kristiansson said.
‘And was he?’
‘No,’ said Kvant.
‘How do you know? What did you do after that cannonade?’
‘We went up and had a look,’ Kristiansson said.
‘There was nobody there,’ said Kvant.
Gunvald Larsson glared at them for at least half a minute. Then he slammed the flat of his hand on the desk and roared, ‘So both of you went up! How the hell could you be so damn stupid?’
‘We each went up a different way,’ Kvant said defensively. ‘I went up the back stairs and Kalle took the front stairs.’
‘So that whoever was up there couldn't escape,’ said Kristiansson, trying to make things better.
‘But Jesus Christ there wasn't anyone up there! All you managed to do was to ruin every single footprint there was in the whole damn bus! To say nothing of outside! And why did you go tramping about among the bodies? Was it to make even more of a gory mess inside there?’
‘To see if anyone was still alive,’ Kristiansson said.
He turned pale and swallowed.
‘Now don't start throwing up again, Kalle,’ Kvant said reprovingly.
The door opened and Martin Beck came in. Kristiansson stood up at once, and after a moment Kvant followed his example.
Martin Beck nodded to them and looked inquiringly at Gunvald Larsson.
‘Are you the one who is shouting? It doesn't help much, bawling out these boys.’
‘Yes it does,’ Gunvald Larsson retorted. ‘It's constructive.’
‘Constructive?’
‘Exactly. These two idiots …’
He broke off and reconsidered his vocabulary.
‘These two colleagues are the only witnesses we have. Listen now, you two! What time did you arrive on the scene?’
‘Thirteen minutes past eleven,’ Kvant said. ‘I took the time on my chronograph.’
‘And I sat in exactly the same spot where I'm sitting now,’ Gunvald Larsson said. ‘I received the call at eighteen minutes past eleven. If we allow a wide margin and say that you fumbled with the radio for half a minute and that it took fifteen seconds for the Radio Central to contact me, that still leaves more than four minutes. What were you doing during that time?’
‘Well …’ said Kvant.
‘You ran about like poisoned rats, trampling in blood and brains and moving bodies and doing God knows what. For four minutes.’
‘I really can't see what's constructive –’ Martin Beck began, but Gunvald Larsson cut him off.
‘Wait a minute. Apart from the fact that these nitwits spent four minutes ruining the scene of the crime, they did get there at thirteen minutes past eleven. And they didn't go of their own accord but were told by the man who first discovered the bus. Is that right?’
‘Yes,’ said Kvant.
‘The old boy with the dog,’ said Kristiansson.
‘Exactly. They were notifed by a person whose name they didn't even bother to find out and whom we probably would never have identified if he hadn't been nice enough to come here today. When did you first catch sight of this man with the dog?’
‘Well …’ said Kvant.
‘About two minutes before we got to the bus,’ said Kristiansson, looking down at his boots.
‘Exactly. Because according to his statement they wasted at least a minute sitting in the car and shouting at him rudely. About dogs and things. Am I right?’
‘Yes,’ mumbled Kristiansson.
‘When you received the information the time was therefore approximately ten or eleven minutes past. How far from the bus was this man when he stopped you?’
‘About three hundred yards,’ said Kvant.
‘That's a fact, that's a fact,’ said Gunvald Larsson. ‘And since this man was seventy years old and also had a sick dachshund to drag along …’
‘Sick?’ said Kvant in surprise.
‘Exactly,’ Gunvald Larsson replied. ‘The damn dog had a slipped disc and was almost lame in the hind legs.’
‘I'm at last beginning to see what you mean,’ said Martin Beck.
‘Mm-m. I had the man do a trial run on the same stretch today. Dog and all. Made him do it three times, then the dog gave up.’
‘But that's cruelty to animals,’ Kvant said indignantly.
Martin Beck cast a surprised and interested glance at him.
‘At any rate the pair of them couldn't cover the distance in under three minutes, however hard they tried. Which means that the man must have caught sight of the stationary bus at seven minutes past eleven at the latest. And we know almost for sure that the massacre took place between three and four minutes earlier.’
‘How do you know that?’ Kristiansson and Kvant said in chorus.
‘None of your business,’ Gunvald Larsson retorted.
‘Inspector