For fans of claustrophobic, vehicle-based horror, David Szymanski’s 2022 hit Iron Lung carved out a uniquely terrifying niche. Pushing players deep into a sea of human blood inside a cramped, blind submarine, the game earned widespread critical acclaim and even inspired an upcoming film adaptation spearheaded by content creator Markiplier. Yet, despite its massive impact and cultural footprint, the video game industry has seen surprisingly few titles successfully capture its specific brand of vehicular dread. While adjacent experiences certainly exist—such as the chaotic deep-sea survival sandbox Barotrauma, or job-based co-op horror titles like Klekta and Shift at Midnight—they largely drift into different gameplay loops. Games like Klekta and Shift at Midnight lean heavily into the emergent, corporate-drudgery chaos popularized by Lethal Company, leaving a distinct gap for solitary, narrative-driven vehicular horror where the vehicle itself serves as both your lifeline and your cage.
This vacuum is precisely why developers and horror enthusiasts are turning their attention toward The Temple, an ambitious upcoming total conversion mod built within the classic framework of Valve’s legendary Source engine. Initially conceived as a short-form project, The Temple adopts the core concept of piloting a vulnerable submarine through alien waters, but it dramatically broadens the scope. Instead of confining players strictly to the crushing depths of an ocean floor, this expansive total conversion elevates the terror across multiple tiers of reality, taking players out of the abyss and launching them all the way into the cold vacuum of space.
Set against the backdrop of a strange aquatic world punctuated by massive, enigmatic concrete megastructures, The Temple tasks players with exploring an eerie and unwelcoming environment using three distinct types of transportation. The submarine serves as the familiar baseline, allowing navigators to plunge into the lightless oceanic trenches where hidden horrors lurk. However, the experience extends far beyond the seabed. Players will also step—or rather, steer—into the cockpit of an atmospheric airship designed for traversing the planet’s sweeping skies and scaling abandoned, tower-like architectural anomalies piercing the clouds. Beyond that, the journey culminates in the operation of a fully functional space shuttle, giving players the capability to break atmosphere and travel outward to the desolate asteroidal moons orbiting the mysterious planet.
The project’s origins trace back to MapLabs, a collaborative modding community that routinely collects and showcases custom maps produced during various Source engine mapping competitions. In its initial release, The Temple was a compact, highly focused two-map experience that could be completed in roughly 20 minutes. While that proof-of-concept release offered a tantalizing glimpse of its atmospheric potential, the upcoming standalone total conversion represents a massive evolution. Creator Klems is currently overhauling and heavily expanding those two original foundational maps while simultaneously developing a brand-new third map. This expansion pushes the projected runtime to over two hours of dedicated, exploration-driven science fiction horror.
A newly released official trailer for the mod offers a comprehensive look at all three vehicles in motion, showcasing the technical and artistic ambition driving the project. For a project built upon the foundational architecture of Half-Life 2, the mod cuts a striking visual profile, demonstrating an acute understanding of scale, architectural dread, and environmental storytelling through colossal, brutalist structures rising out of the water. Beyond the machinery, the mod incorporates psychological horror elements reminiscent of classic indie titles like Amnesia: The Dark Descent, featuring invisible water-based monsters that ripple the surface and stalk the player through audio cues and subtle environmental disturbances. Adding a layer of bizarre companionship to the isolation is a talking crow—or at least, an avian entity whose complex corvid language players can somehow understand—which acts as an enigmatic guide through the unfolding mystery.
These elements combined have positioned The Temple as one of the most anticipated community projects within the classic PC modding scene, particularly for enthusiasts of atmospheric dread and unconventional horror mechanics. While developer Klems has not yet locked down a definitive calendar release date, the creator has indicated that the standalone mod is slated to launch very soon, potentially arriving as early as next month.
