In the realm of The Last of Us, peril is always imminent — and even the apparently safe refuge of Jackson might not be as protected as it seems.

Though Ellie (Bella Ramsey) and Joel (Pedro Pascal) have discovered a temporary sanctuary within the fortified community, dangers are escalating from every direction. A relentless Abby (Kaitlyn Dever) is advancing, new and horrifying varieties of Infected are surfacing, and — perhaps most alarmingly — there could already be an unseen threat hidden within Jackson itself.

At the conclusion of Season 2, Episode 1, a concerning visual prompts inquiries: What’s occurring with the Cordyceps fungus identified in the town’s plumbing?

What’s going on with the pipe in Episode 1?

Joel has assumed a leadership position in Jackson, assisting in the oversight of the town’s building and infrastructure. However, as Dina (Isabela Merced) informs him, they are encountering significant plumbing challenges.

“The main lines are clay, all cracked to hell and filled with roots; we don’t really know what we’re supposed to do,” she tells him.

Joel’s suggested remedy? “Saw out the broken sections, pull the roots, and we’ll patch the holes with some ABS.”

It seems like a simple fix — until the episode’s final moments unveil something considerably darker. Among the roots within the damaged pipes are the unmistakable tendrils of the Cordyceps fungus.

Is Jackson in danger from the Cordyceps in the pipes?

Regrettably, yes. While merely touching the Cordyceps roots does not lead to infection — that still necessitates a bite — Season 1 clarified that the fungus is part of an extensive, interconnected network. Those fungal tendrils within the plumbing are not just sprouting — they are communicating.

This implies that as long as the sewer lines remain unprotected, the fungus could be sending out signals to nearby Infected, effectively notifying them of the existence of a flourishing human settlement just over the ridge.

In other terms, Jackson may be unwittingly sending an open invitation to the Infected.

The Last of Us Season 2 debuts April 13 at 9 p.m. ET on HBO and Max.