In her beautifully poetic book ‘On Photography’, Susan Sontag describes a so-called ‘involuntary memory’ that Marcel Proust applied in his remembrance-fuelled writing. Bleak footprints of the past mix with the meshes of reality so powerfully sealed within us that they cannot be erased. Photography and the archive carry an elusive notion of depicting reality, yet they can also take us on an uncanny journey into worlds that are barely tangible and only just visible. The latest exhibition at the Library of Birmingham ‘Album 31’ epitomises the idea of a photograph that is a trace of reality and, most importantly, an encounter with the unreal more