But then again they’re all students in departments located in the town center, and they might have bumped into each other without realizing it. A nightclub, the student union, a political party, handball, bird-watching, any damn thing. Fraternities with strippers jumping out of cakes and giving a few blow jobs. Maybe that’s what it is, and so they think they’ve got a good reason to lie about it. Or a student disco. No doubt they still have them at the union. It’s got to be more likely than not that they’d run into each other somewhere or other.”

“OK,” said Ringmar. “But so what? Was their attacker there as well?”

“I don’t know. But it’s a possibility.”

“So he was specifically out to get these three?”

“It’s a hypothesis,” said Halders.

“But you could just as well say he was ready to attack anybody at all he happened to come across,” said Ringmar. “Late, deserted, a drink or two to dull their wits.”

Halders got to his feet and walked over to the wall map of Gothenburg. He stretched both arms back over his shoulders, and Ringmar could hear his colleague’s joints creak. Halders glanced at him with what might have been a little grin, then turned to the map again and put his finger on it.

“Linnéplatsen the first time.” He moved his finger to the right. “Then Kapellplatsen.” He ran his finger downward. “And now Doktor Fries Square.” He turned around and looked at Ringmar. “A pretty limited area.” He looked back at the map. “Like a triangle.”

“Not all within walking distance, though,” said Ringmar.

“There’s such a thing as public transportation.”

“Not much of it late at night, though. No streetcars, for instance.”

“Night buses,” said Halders. “Or maybe the Hulk has a car. Or he just walks. The attacks weren’t all on the same night.”

“But why change location?” asked Ringmar.

“He probably thinks we have enough resources to keep an eye on the previous place,” said Halders. “So he doesn’t go back there.”