If this past year-and-change has taught us anything, it's how interconnected we all are — a bat coughs and the world gets sick. Vaccines aside, our greatest weapon for defeating Covid-19 has been the mask, an accessory I'd formerly appreciated only a symbol: masks make secret, masks hide, masks cover, in protests as in pandemics. The social value of the mask has been made clear: they're not deceptive so much as protective, of ourselves and of others too. Masking is a mutual responsibility, a symbol of common identity founded in a common hope.