Why alienate the last person on this earth who still takes me seriously? I try to think of something to say to make it better. Lewis holds his hand up. ‘Wait, Ali. I’m thinking.’ He smiles. Is that a sad smile – because he’s finding the words to tell me our friendship is over – or a smile that says, ‘I get it now’? ‘I don’t know what I was expecting, but it wasn’t that,’ he says eventually. ‘It’s the perfect storm for me. I’m a scientist. A rational person. I believe in matter and gravity and what’s observable. Evidence.’ ‘I know, Professor.’ He smiles again. ‘I’m not convinced there’s an afterlife. I’ve always thought we invented it to make us feel better about the big unknown. Wouldn’t bet my life on it, but, you know, odds on we die and, well, that’s it. Except for the memories of us that the living hold on to. That’s how we stay alive.’ I nod. I’m not noticing the restaurant any more.