Whilst it becomes clear that Treister is keen to place genuine historical research at the core of Intervention, it is more interesting to consider the way in which she manipulates these factual elements in order to prompt  ambiguity between truthful historical “facts” and science fiction style “invention”.  Firstly, we are told that the crystal device has been indefinitely removed for “conservation” reasons (figure 6).1 Secondly, we are only shown a (rather crude) representational drawing of the object (if it really exists, why not a photograph? - has it really been removed from “conservation” reasons?). Thirdly, Our suspicions are strengthened further when it is suggested that the drawing has been “lent” to the museum by Treister/Brodsky (If the object exists why does the museum not have its' own record, most especially is it has been removed for “conservation” reasons?).

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For Treister there is a specific motivation behind this subterfuge. In an interview with academic Roger Luckhurst, Treister suggests that the question of “how informed the audience is” and their capacity to “distinguish between what may be actual and what might be invented” is central to the work: there will be “varying degrees of slippage, and that is interesting in itself.  1 It is worth noting at this point that photographs of Dee's scrying device do actually exist, but Treister has chosen quite deliberately to exaggerate this sense of “slippage” by hiding the evidence (figure 7). Through the choice to exclude photographic evidence of Dee's crystal, Treister can be seen as engaging with one of the defining arguments surrounding ocularcentric discourse  – that of the visions ability to distinguish between truth and illusion -2 or in other words how much we can actually believe what we see.

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Treister's decision to create this ambiguity through the manipulation of photographic evidence is pertinent, given that arguments surrounding notions of visual truth and illusion most commonly centre on the photographic image. From its inception, the camera was widely heralded by the scientific community, on the assumption that it fulfilled “so many of the criteria deemed necessary for good scientific observation.1 Seemingly devoid of subjective human agency, the camera was regarded as “mechanical, and so indefatigable. It was indiscriminate, and therefore objective. It was optical, and consequently reliable”2.  These Perceptions borrowed heavily from seventeenth century philosophies. 3 For example, Descartes developed theories derived from practical scientific investigations, in which it was discovered that the lens from the eyeball of a large animal (such as an ox, or recently dead human) acted in much the same way as the camera obscura – a device regarded as an indiscriminate, scientific viewing machine. To many early nineteenth century commentators it logically followed that terms such as methodical, objective and truthful  could be applied to the newly emerging camera technology.4



The idea that camera technology could act as a methodical, objective, scientific instrument is highly relevant to Hexen. This is the case not only in respect of the suppression of photographic evidence as shown in Intervention, but also in relation to those images that Treister actually does display. The viewer is confronted with a number of photographic images, including The Ministry of Defence (London), West Point Military Academy (USA), Microphones 1940's-50's and Various artefacts (figure 8 & 1). These are photographs of real institutions, and real artefacts, conjuring up associations with photographic archives or meticulously curated museum displays. Treister complicates the viewers perception of these seemingly “objective” images by juxtaposing them against some clearly faked photographic material. For example, we are shown Treister's futuristic time travelling alter-ego, Rosalind Brodsky with the Hollywood producer Sam Goldwyn during the nineteen forties (Rosalind Brodsky and Sam Goldwyn in Hollywood figure 9)  and again, in the unlikely setting of the Chernobyl 3-core (figure 9).