Even before a global pandemic introduced us to terms like social distancing, loneliness was already becoming the defining condition of the twenty-first century. Carl, the Los Angeles media executive so lonely he pays to be cuddled. Eric, the Parisian baker finding community in the political far right. Peter, the London schoolboy distraught because no one 'likes' his Instagram posts. All around us, the fabric of community is unravelling and our personal relationships are under threat. And technology isn't the sole culprit; equally to blame are the dismantling of civic institutions, the radical reorganisation of the workplace, mass migration to cities, and decades of neoliberal policies that placed self-interest above the collective good. This is not merely a mental health crisis. Loneliness increases our risk of heart disease, cancer and dementia. Statistically, it's as bad for our health as smoking fifteen cigarettes a day. It's also an economic crisis, costing us billions annually, and a political crisis, with feelings of marginalisation fuelling divisiveness and extremism around the world. But it's also one we have the power to reverse. Combining a decade of research with first-hand reporting, Noreena Hertz takes us from a 'how to communicate in real life' class at an Ivy League university to encounters in German beer gardens between people with radically different political views, from 'renting a friend' in Manhattan to nursing home residents knitting bonnets for their robot caregivers in Japan. Offering bold solutions ranging from compassionate AI to innovative models for urban living to new ways of reinvigorating our neighbourhoods and reconciling our differences, The Lonely Century offers a hopeful and empowering vision for how to heal our fractured communities and restore connection in our lives.