Understanding science is the only way to understand the microbe—SARS-CoV-2—and what it does to our bodies. Fighting a pandemic requires a well-functioning public health system. The crisis created by the Covid-19 pandemic in the ‘advanced countries’—supposedly the best prepared—has shown us the peril of hollowing out public health systems to make way for ‘efficient’ privatized healthcare. This time in our collective lives, a global pandemic, is the right time to recall Amit Sengupta. He should have been here to help us understand what we are going through, why we are where we are, and the way forward. But he is not here. This volume, of which this is the introductory chapter, attempts to recall his life, his ideas, his convictions. We see that the pandemic brings out the three elements that defined Amit’s work: as a science activist, a health activist, and a political activist. He made no pretence that he viewed science and health activism through the prism of his politics. He chose this battlefield since he was trained as a doctor. He did not believe that the doctor’s job was just to heal sick individuals; the bigger task—perhaps the real task—was to build a society with a system to prevent its people from getting sick. And if people do get sick, such a system, in such a society, will care for them whether or not they can pay for treatment. In other words: health is a fundamental right of a citizen. Capital’s objective—both Big Pharma and private healthcare—is to profit from people falling ill. This is the fundamental contradiction between capital and people. Amit knew this. [This is the Introductory Chapter of the volume, Political Journeys in Health - Essays by and for Amit Sengupta edited by Prabir Purkayastha, Indranil and Richa Chintan published by LeftWord.]