Helen Lewis Has Left the Chat.

The rise of instant messaging has made our social and professional lives faster, more casual — and more chaotic. But amid all the discussion of the effects of public social media, such as Facebook and Twitter, there has been relatively little attention paid to private social networks—the direct message and the group chat — and how they are shaping our relationships and our world.

In this series, Helen Lewis looks at the secret world of instant messaging, meeting a woman who married a chatbot, discovering how Russian dissidents are fighting a propaganda war, and hearing the inside story of how Britain ended up governed from a single WhatsApp group.

It's a strange new world where workplace rebellions are conducted through duelling emojis and military secrets are traded on chat forums about a children's cartoon. It's also a world where you can never be quite sure who you're talking to—and who's eavesdropping on you.