Fragile Fortress, Stable Ruin and the Restriction of Women: An Exploration of Imaginary Space in the Locked-Room Mystery’
I determined to lock, bolt and barricade my door…I secured myself against all intrusion; looked under the bed, and into the cupboard; tried the fastening of the window; and then, satisfied that I had taken every proper precaution. 
[I] followed Lawrence along the passage and the gallery… John rattled the handle of Mrs Inglethorp’s door violently… It was obviously locked or bolted on the inside… John opened the door of his room… We went straight to the connecting door. That, too, was locked or bolted on the inside… 'We must try and break the door in…Now then, we’ll have a try at the door…isn’t there a door into Miss Cynthia’s room?'… The framework of the door was solid… and finally, with a resounding crash, it was burst open. 
‘Contraction of eye pupils; heavy breathing when stirred; pallor; clammy skin; congestion; hallucinations. Didn’t I tell you? She told us that mad story—’ 
Using words like these above, the authors of Locked-Room Mysteries use their pens to construct numerous imaginary spaces for readers to read, investigate and experience. As Savoye argues, modern detective stories enshrine rational positivism as the ultimate truth and are born out of the new certainties established by the Enlightenment Century; whether it is Paris, London, or Los Angeles, the detective story is intrinsically linked to the urban environment, which is where the myth of truth is best expressed. 
The Locked-Room Mystery endeavours to construct a locked room, a space that seeks authenticity of the real world and attempts to provide an ultimate answer and a testing ground for the revelling of the mystery. This space emphasises a comparative authenticity as a counterpoint to the real world, and it changes and reconfigures itself as society changes. It is in this process that the space is repeatedly depicted in the form of texts, illustrations, maps and plans, a depiction that derives from a shared perception of the space as a typical place between the author and the reader; thus, the imaginary space becomes more than a projection of the reality, but rather a vivid representation of it.
However, despite its popularity with readers, the Locked-Room Mystery has rarely been systematically studied as a genre, let alone the imaginary space constructed within it. This thesis aims to fill this gap by employing an architectural-historical lens to explore how the relationship between social reality, historical context, and the writing of the Locked-Room Mystery influences the construction of the imaginary space within it and how these relationships interact with each other.
Therefore, I proposed three main questions:
1. In the context of the development of modernity, how does the imaginary space within the Locked-Room Mystery reflect the dynamics between public and private spaces?
2. How does creating the space in the Locked-Room Mystery reflect the relationship between imagination and reality?
3. How do the imaginary spaces within Locked-Room Mysteries represent and further influence women's experiences in the real world?
To address these questions, I utilise literary criticism as my primary methodology. By selecting representative texts of various periods within the genre and conducting textual analysis, I aim to explain issues related to spatial dynamics and gender. Therefore, the thesis is structured in a semi-chronological manner and revolves around the three main issues above.
Firstly, this type of imaginary space has its origins in the impact of anxiety on the spiritual world brought about by modernity, and its spaces resemble the result of a fortified fortress turning fragile. People are forced to construct a relationship with the city, which in the spatial structure of the Locked-Room Mystery is reflected in the invasion of public space into private space. Crime contagiously appears in the most domestic and private spaces where there is no escape. The spaces constructed in short stories by authors such as Edgar Allan Poe, Wilkie Collins, and Arthur Conan Doyle are characterised by this allegory. This fear stems from the modernity-induced crisis in the meaning of dwelling places and ultimately manifests as imaginary space.
Secondly, as the socio-historical context changes, the imagination is distanced from reality and the space changes further. The troubled political and social conditions brought about by the world wars both influenced a fundamental shift in the purpose of this type of imaginative expression and created a boom for the genre. The fragile fortress shifted to a stable ruin waiting to be dug into. In contrast to the earlier anxiety that isolated private spaces would no longer remain detached, the types of this imaginary space in the interwar period endeavoured to shape an isolation that was close to reality. They are like a parallel line of reality, similar but never exposed to the danger of being touched or harmed by reality. Therefore, to provide such a sense of security, the shaping of the spatial structure also becomes a quest for efficiency and standardisation, quickly establishing a shelter for the reader through the choice of simpler, direct-functional architectural elements.
Finally, introducing feminist criticism is extremely important for such a male-dominated genre, and here, because of the loss of women's work, I have sought instead to provide a feminist theoretical entry point for this type of work. The search for the women re-genders the text.  The limitations women face in the real world are honestly reflected in the spatial structure of the Locked-Room Mystery. More importantly, the female characters' bodily experiences within such spaces are repurposed to aid in defining a legitimate woman in the city. However, as Lefebvre argues, although space is used as a means of control and power, it still partially escapes those who use it to dominate.  The restriction added on women in the Locked-Room Mystery exists, but there is still more to explore, a future journey in the look for the woman.
In conclusion, this dissertation develops the possibility of conducting an architectural history study of the little-studied genre of the Locked-Room Mystery to understand how this space is constructed and relates to the historical context. In this study, I focus on the text of the Locked-Room Mystery itself, attempting to restore a dynamic construction of imaginary spaces from literary traces and ultimately confirming that this construction is closely related to social reality. In the genre of Locked-Room Mysteries, the imaginary space is distinct for its static nature and central role—qualities rarely seen in detective fiction.
Throughout my exploration and analysis of the works within this unique genre, I have come to appreciate the richness of its expression as a representation of space. It goes beyond the metaphorical, functional, and restrictive spaces that I previously proposed. Therefore, future exploration of these spaces, whether as fortresses, ruins, or cages, is both necessary and significant.
 Wilkie Collins and Julia Thompson, The Complete Shorter Fiction (London: Robinson, 1995), 82.
 Agatha Christie, The Mysterious Affair at Styles (New York: Bantam Books, 1965), 19-20.
 John Dickson Carr, It Walks by Night (London: Harper and Brothers Ninety, 1930), 81.
 Daniel Ferreras Savoye, 'Detective Fiction and the Myth of the Urban Truth,' Ángulo Recto: Revista de estudios sobre la ciudad como espacio plural4, no. 2 (2019): 25.
 Lucy Sussex, 'Women Writers and Detectives in Nineteenth-Century Crime Fiction: The Mothers of the Mystery Genre,' in Crime Files, ed. L. Sussex (London: Palgrave Macmillan UK, 2010), 1.
 Henri Lefebvre, The Production of Space, trans. Donald Nicholson-Smith (Oxford: Blackwell, 1991), 26.