I love all of Dying Light: The Beast's incredible side quests, but one of them was so powerfully horrifying I thought it was a main mission

Some game stories can be a little predictable, but I'm proud to say that Dying Light: The Beast is anything but. Even if you manage to work out who The Beast is long before its identity is confirmed around the game's midpoint – something, surprisingly, I did not – the plethora of side quests offer plenty more surprises you definitely won't see coming.

For Your Mind Only is one of them. Tasked with exploring an abandoned train tunnel at the behest of a groovy NPC nicknamed Starchild, I'm thoroughly unprepared for what awaits me in those dark tunnels. What transpired was an experience that put my hairs on end, my stomach in knots, and had me in absolute disbelief that this was not a story quest at all, and it all starts with a screaming voice in my head...

Warning: Story spoilers for Dying Light: The Beast ahead!

We are legion

By the time this particular quest rolls around, I'm pretty close with Starchild. One important thing to note about the 70s-coded ageing hippy is that he, much like the rest of his fellow cave-dwelling outcasts, is a sentient Infected with telepathic abilities – something anyone who played Dying Light: The Following back in 2016 might find familiar.

I'd already given Starchild a hand in an earlier mission chain, one that delved into Kyle's own tortured psyche, allowing him to study Kyle in the hopes of gleaning some new insights on his condition that could benefit the outsider enclave. But this time, he has a different problem.

For Your Mind Only begins with Starchild summoning Kyle back to the outcasts' cave. There's a deadzone not far from there where the group's telepathic abilities stop working, which is a problem since that's how everyone communicates their safety and whereabouts in this group. It's Kyle's mission to investigate the area – near an abandoned railway tunnel, Starchild says – and find the cause of this psychic stoppage.

Over I hop to the railway tunnel, where I clear a horde of Biters in time to catch the last dying words of a badly injured sentient Infected. She warns Kyle to run, fast, before asking for her son Ricky. The name rings a bell – I recall seeing Ricky mentioned on a scribbled note found in a house of newly-turned Infected as part of an earlier Starchild mission. The note claimed that they could hear Ricky's voice in their heads, tormenting them as they gave in to the infection coursing through their bodies.

As Ricky's mother dies, I turn my attention to the tunnel. Clearly, Ricky is a fellow sentient Infected, meaning he likely has telepathy too. Kyle approaches the tunnel, and suddenly, a voice pierces his mind just as Starchild's starts cutting out a scrambled radio signal. Help us, it begs. And I do.

After clearing the tunnel entrance of The Baron's soldiers, the voice talks to me again, urging Kyle deeper into the tunnels and through a maintenance door. The presence of Biters makes me jump – but again, the voice soothes my woes, tells me not to worry – we won't hurt you, it says. To my surprise, it's telling the truth. I start to move cautiously through the throngs of Infected, and though they regard me with cold, distant eyes, not a single one moves in to attack.

If that wasn't unnerving enough, the tunnel itself seems to be… alive. I start spotting knots of fleshy, pulpy growths, like tumors squeezed through gaps in the rusty metal. The further I go, the more I see – and upon closer inspection, they most certainly are writhing. It's hard to describe just how horrifying a sequence this is, moving through passageways clotted thick with Biters and sticky red globules, silent save for the occasional groan or snapping jaw. The deeper I go, the more panicked I get; whatever is in control of these things could fail at any point, leaving me outnumbered and fighting for my life in this darkened hellhole.

It's such an atmospherically rich, emotionally fraught scenario that I can't quite believe it's been relegated to side quest territory. When I'm confronted by Ricky, who has been devoured and incorporated into the Infected's hive mind, that feeling only intensifies. It turns out that Ricky could exert control over small groups of Infected, using his telepathic gift to manipulate their movements. But when he tried to exert that power here, he was the one who ended up used and assimilated into this legion entity.

What happens from there, I don't want to spoil. But what I will say is that Techland here pulls off some of the most stunningly disturbing narrative twists and visuals I've ever seen among the best survival horror games yet. It's a true testament to the level of detail the developer has put into every moment, even knowing full well that players might never see it, and I think I'll be seeing that flesh-pocked railway tunnel in my nightmares for the foreseeable.

We're shining a spotlight on Techland's latest for this month's On The Radar series. Check out my 4.5-star Dying Light: The Beast review for more on why I loved it so much!