Pretty much every loose end to the freewheeling scandal that has rocked the White House, claimed the career of CIA director David Petraeus, and may yet take down General John Allen, the US Commander in Afghanistan, now leads to the vast red brick mansion, a short drive from Florida’s MacDill Air Force Base, that the 37-year-old Jill Kelley calls home.

She has become the key player in a saga which is sending ripples through the military establishment. Her social relationship with several senior army and intelligence figures is now under the spotlight. And what we learn about her public and private lives may have far-reaching implications for America’s national security.