Membranes - porous biological interfaces which regulate flows between one zone and another - are the foundational image for an issue guest-edited by Granta contributor and best-selling novelist Rana Dasgupta.

Featuring new poetry from Andrew McMillan and Tishani Doshi, photography from Ruchir Joshi, Arturo Soto Gutierrez, Monica de la Torre and Anita Khemka, as well as cutting-edge fiction and thought-provoking essays:

Fatin Abbas on the border between Sudan and South Sudan

Lydia Davis on faultlines in families

Mark Doty on homelessness in New York City

Anouchka Grose on infidelity and the idea of the unwanted third

Daisy Hildyard on membranes in the human body

Adam Jasper on Christian Enzensberger and 'smut'

Kapka Kassabova on lakes and Europe

Anita Roy on the newt

Eyal Weizman on contemporary architectural strategies for repelling and dividing people

Rana Dasgupta is an award-winning, best-selling writer. His novels include Tokyo Cancelled and Solo, winner of the 2010 Commonwealth Writers' Prize. His non-fiction book Capital won the 2017 Ryszard Kapuscinski Award for Literary Reportage.