Your phone rings, “You have been selected… your help is required … time is running out…” Searching for objects from the lost index holds the key to stabilising the changes. In response to their actions participants receive phone calls – fragmentary updates from which possible stories build. But as time runs out the uncertain future draws nearer and so too does the metamorphosis of the museum. Binaural soundscapes layered with ambient sounds stimulate perceptual illusions and combine with attention focusing techniques to alter the perception of the environment.
The locative narrative The Lost Index: NATMUS was featured at 8th International Conference on Interactive Digital Storytelling in Copenhagen.
Audio guides and games have long been staple modes of interpretation in museums. The medium of locative narrative, defined here as participatory site-specific story experiences that are heard on headphones, offers alternative modes of engagement with archives and collections where the visitor becomes a participant in an unfolding drama. The confluence of the existent world and narrative representations is an often-reported feature of “mixed reality”  experiences   .
The Lost Index: NATMUS (2015-) , produced by Trulyimagined, aka Emma Whittaker and James Brocklehurst, is an interactive narrative that transforms the location of a museum into a dystopian story world. Situated at The National Museum of Denmark and the DieselHouse museum it explores how participants can experience the story across spatially distributed locations.
Binaural compositions simulate the aural qualities of the fictional locations whose sounds are plotted temporally and spatially within the different museums’ rooms. Sounds are movement responsive and triggered by participants’ own smartphones through novel uses of Bluetooth low energy ‘iBeacons’. As the drama proceeds, the recorded auditory dimensions of the rooms’ subtlety change that can affect the interpretation of sounds as live, recorded or imagined.
Participants, in the role of protagonist, move simultaneously within the story’s locations and museum, physically situating the player within a fictional world of the game. The Lost Index: NATMUS develops William James’s  radical empiricist insight as an approach to interactive narrative that plays with the contexts of players’ beliefs, directing and misdirecting their attention and keeping knowing in transit.
The Lost Index: NATMUS can be downloaded from the iOS App Store for use at The National Museum of Denmark, Copenhagenand the Dieselhouse museum, Copenhagen. Headphones are required.
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 Whittaker, E. & Brocklehurst, J. R. (2015) ‘The Lost Index: NATMUS’ [iOS Application]. Apple Inc. [https://itunes.apple.com/us/app/the-lost-index-natmus/id1058419473?mt=8]