"He must be on his way," Wallander said. "Let's start without him."

Martinsson leafed through a stack of papers. Then he pushed a postcard over to Wallander. It was an aerial shot of central Vienna.

"This is the card that the Hillström family found in their letter box on Tuesday, 6 August. As you can see, Astrid Hillström says that they're thinking of staying a little longer than they had originally planned. But everything is fine and they all send their regards. She asks her mother to call around and tell everyone that they're well."

Wallander read the card. The handwriting reminded him of Linda's. It was the same round lettering. He put it back.

"Eva Hillström came here, you said."

"She literally burst into my office. We knew she was the nervous type, but this was something else. She's clearly terrified and convinced that she's right."

"What's she so sure of?"

"That something's happened to them. That her daughter didn't write that postcard."

Wallander thought for a moment. "Is it the handwriting? The signature?"

"It resembles Astrid Hillström's writing. But her mother claims it's a very easy style to copy, as is her signature. She's right about that."

Wallander pulled over a notebook and a pen. In less than a minute he had perfected Astrid Hillström's handwriting and signature.

"Eva Hillström is anxious about her daughter's welfare and turns to the police. That's understandable. But if it isn't the handwriting or the signature that's worrying her, then what is it?"

"She couldn't say."

"But you did ask her."

"I asked her about everything. Was there something about the choice of words? Or was there something in the way she put it? She didn't know. But she was certain that her daughter hadn't written the card."

Wallander made a face and shook his head. "It must have been something."

They looked at each other.

"Do you remember what you said to me yesterday?" Wallander asked. "That you were starting to get worried yourself?"