When Alice Salmon died last year, the ripples were felt in the news, on the internet, and in the hearts of those who knew her best.

But the person who knows her most intimately isn't family or a friend. Professor Jeremy Cooke is an academic whose life has become about piecing together Alice's existence in all its flawed and truthful reality.

For Cooke, faithfully recreating Alice's life - through her diaries, emails and anything using her voice - is all-consuming. He does not know how deep his search will take him, or the shocking nature of what he will uncover.