If the 20th century popularised the figure of the émigré, the 21st has introduced that of the returnee, who, aided by a combination of Skype, social media and cheap air travel, doesn’t so much exchange countries as exist between them. ‘I was an émigré. I had left. Now I’d returned,’ announces Andrei Kaplan, somewhat incredulously, in Keith Gessen’s vigorously funny second novel.