The Gap In The Light is emerging company Engineer Theatre Collective's third production and their first foray into the genre of psychological horror.
It is a play of two strikingly different halves, starting with the auditorium in total blackout, the only illumination coming from torches held by the cast or attached to their helmets.
In the first act, we are introduced to British PhD student Hana, in Mexico for research, and Ethan, her American–born guide, as they embark on a tour of underground caves in which Hana hopes to find ancient pottery remains.
As Hana and Ethan descend to 500 feet below ground level, they enter a different world with its own ecology and soundscape. Once down there, they explore the uncharted passages and ducts of their temporary underground home, not knowing what, if anything, they will find.
Tension is ratcheted up as it transpires that the place has special meaning for the native-born peoples for whom the site is sacred and Hana explains to Ethan that nearby geological digs exposed remains of humans believed to have been killed in sacrifice.
Events which I have no appetite to reveal cause the first act to end dramatically and, as the lights slowly came up, a "dum … Dum … DUM!" sounded in my head.
The action of the second half of the play takes place in Hana's London home which she shares with her partner, Daniel.
She has been back a while and is now pregnant. Life looks normal on the surface and, although she has shelved her PhD project, she continues to be haunted by events that took place in Mexico.
Suffice it to say that as the second act came to a close my head was ringing with the theme tune to The Twilight Zone.
The first half of The Gap In The Light is for me the more affecting and engaging one because the narrative and the physical action have a stronger impact. In the second, naturally lit, act there is less tension, the story being eerie rather than scary.
I enjoyed watching the first act because of the absence of the visual stimuli that are usually taken for granted.
The light there is is white and funnelled. It distorts the features of the actors, bleaching from their faces any nuance of expression and making movements hard to distinguish.
In the total blackness, responding to the play becomes a much more private experience; I found myself watching and listening with greater acuity.
The soundscape to the first act is very atmospheric, which helps build a tension that is sadly reduced in the second, the plot of which follows a familiar arc rather too fuzzily and could do with more startling frights.
The Gap In The Light might deal with the stuff of nightmares but is unlikely to induce any.