Camilla agreed. "I know, it's a ridiculous story. I think he actually expected me to believe it, which is also ridiculous."

Something dangerous -- he wouldn't have gone somewhere dangerous with people he didn't know and trust. He didn't know Professor Dax or Dr Silvey very well at all. So it hadn't occurred to Camilla that it might be something of that nature. Anyway, he's perfectly fine. He's sending postcards.