Jacob Sager Weinstein has written for The New Yorker, HBO and the BBC. He is also a former contributor to The Onion and has won a Writers' Guild of America Award. Now living in London with his family, Jacob thought of the idea for The City of Secret Rivers, the first in his children's fantasy trilogy, while walking along the Thames Embankment, as he started thinking about London's secret underground rivers and "discovered that London's history is so magical that it only takes the slightest of tweaks to make it into a fantasy story." Follow Jacob on Twitter @jacobsw.