In the best sort of antiques store or second-hand bookshop you will often find heaped up remnants of literate culture on the brink of extinction, thrifty oddities of survival clinging to the shelves: unappetising cookbooks, compendiums of humour from also-ran television comedians, lively tracts addressed to now-inert controversies. (In one of my favourite discoveries, an English clergyman soberly considers the evidence for the theory, briefly entertained in the early 1970s, that Jesus was a psychedelic mushroom around whom the early Christians had formed a fertility cult). This material is both physically and semiotically mouldering, turning to mulch; it has not so much an aura as a miasma about it. It is into this mephitic element that Southend-on-Sea-based writer, artist and performer Sophie Sleigh-Johnson’s Code: Damp learnedly infiltrates itself, following lines traced by capillarising marsh-moisture from its tell-tale bloom on 70s sitcom wallpaper.

The thesis, in outline, is that the sitcom career of British actor Leonard Rossiter, hagiographically apostrophised as a mediaeval Seynt Lyonard and in due course brought into telepathic connection with twentieth-century French philosopher Jean-François Lyotard, manifests and harnesses latent cultural forces whose code is written in the microbial efflorescences of suburban grime and grot. From Rising Damp (which first aired in 1974, the year of publication of Lyotard’s Libidinal Economy) to the late 1970s’ The Fall and Rise of Reginald Perrin, Rossiter acts as a conductor of strange energies, a grotesque psychopomp, through whom something of his cultural moment — and of the pasts and futures routed through that moment’s unstable postwar architecture — can be divined.

The Leonard-Lyonard-Lyotard chain is characteristic of the way Code: Damp moves from signifier to signifier: laterally, gnomically, mixing up archeological epochs and strata to make connections that seem cross-wired on the face of it but as often as not pay off in surprising ways. We are operating here in a ‘Flat Time’ in which the ancient and the modern are compressed into a single imaginary body through which damp unstoppably permeates, spatially and temporally, writing itself on partition walls in a process Sleigh-Johnson calls ‘de(sur)facement’. The same ‘grotty carrier bag,’ she writes at one point, may hold ‘your Pan Horror book, cuneiform tablet and can of Holsten, such that the carrier bag merges all examined figures thus far into bathetic gestalt.’ Here, ‘perichoresis, interpenetration’ is the order of the day.

It quickly becomes apparent that the book isn’t in any straightforward sense a ‘guide to British sitcoms’ (even an ‘esoteric guide’), as advertised by its subtitle. It is rather a serious, scatty and compulsively wit-propelled attempt to inhabit their material and psychic milieu, from the perspective of an unwelcome but omnipresent non-human agent: de(sur)facement as autobiography of rot. Code: Damp’s is the weird 1970s of what the parapsychologist Rupert Sheldrake later named ‘morphic resonance’ as an animating conceit of children’s fiction (Alan Garner’s The Owl Service and Red Shift) and television horror drama (Nigel Kneale’s The Stone Tape) alike. Things and places are imbued with traces of memory, the past is never fully past, the future may likewise be summoned through oracular ruptures and outré juxtapositions. Where the by now familiar lexicon of ‘hauntology’ can lend all of this a somewhat airy, spiritualised numinosity — aura, not miasma — Sleigh-Johnson is primarily, and refreshingly, interested in developing a metaphorics of the stuff that climbs the walls and squelches underfoot: damp as hypo-object.

I was alternately baffled and tickled by Code: Damp’s permutation of academic syntax with far-fetched word choices, which sometimes yields sentences which feel as if they are just on the verge of making sense: ‘TV plays that can thus loosely be termed “folk horror” stretch the credulity of both the industrial and the bleakly empty as inseparate to the numinosity of ploughed fields.’ If you squint at this, you can make out an observation that elements of supposed ‘folk horror’ are often transposed from the rural cliché in which they supposedly originate into settings where the ‘folk’ label might seem incongruous. It’s an odd way to put it, some readers might find this off-putting, but I think it’s best accepted and enjoyed as part of the fun. Like The Fall’s Holsten drinking Mark E. Smith, one of the presiding genii of the text, Sleigh-Johnson sees language itself not as a neutral medium of communication but as a palimpsest of inscriptions with its own unstable architectonics, intrinsically perverse and perverting. Her prose sports its own bloom of mould, irruptions of arcane and obsolete terms defacing its surface: ‘old cuneiform letters haemorrhage into the page you’re now reading.’

Towards the conclusion of the book Sleigh-Johnson imagines it sharing the fate of the yellowing paperbacks and static-tormented VHS cassettes that have survived from its period of interest, hoping that it in turn will be ‘found in decades to come, in an old pub in Essex somewhere, a forgotten pamphlet on a shelf, a Lutheran Flugschriften considered the soiled and strange ramblings of a post-industrial estuary cult.’

An early-2000s Cultural Studies-style ‘reader’ on the world of Rigsby and Reggie Perrin would have been enjoyable, no doubt, but there can be something hands-off and antiseptic about the way academia (and contemporary fandoms wielding a hermeneutic gifted to them by academic pedagogy) methodically wring sociological insight out of cultural texts. Code: Damp attempts something muckier and more compromised, crazed with divagations and riddled with in-jokes, but singularly and illuminatingly devoted to its object.