Martinsson nodded. "Something doesn't add up," he said. "I just can't put my finger on it."

"Let's put the question another way," Wallander said. "If they haven't left on this unplanned holiday, then what's happened? And who's writing these cards? We know that their cars and their passports are missing."

"I'm obviously mistaken," Martinsson answered. "I was probably influenced by Eva Hillström's anxiety."

"Parents always worry about their children," Wallander said. "If you only knew how many times I've wondered what Linda was up to. Especially when you get postcards from strange places all around the world."

"So what do we do?" Martinsson asked.

"We continue to keep the situation under surveillance," Wallander said. "But let's go over the facts from the beginning, just to make sure we haven't missed anything."

Martinsson summarised the events in his unfailingly clear fashion. Ann-Britt Höglund had once asked Wallander if he realised that Martinsson had learned how to make presentations by observing him. Wallander had scoffed at this, but Höglund had stood her ground. Wallander still didn't know if it was true.

The chain of events was simple enough. Three people, all between the ages of 20 and 23, decided to celebrate Midsummer's Eve together. One of them, Martin Boge, lived in Simrishamn, while the other two, Lena Norman and Astrid Hillström, came from the western part of Ystad. They were old friends and spent a lot of time together. Their parents were all wealthy. Lena Norman was studying at Lund University while the other two had temporary jobs. None of them had ever had any problems with the law or with drugs. Astrid Hillström and Martin Boge still lived at home; Lena Norman lived in halls of residence in Lund. They didn't tell anyone where they were planning to hold their Midsummer's Eve party. Their parents had talked to one another and to their friends but no one seemed to know anything.