The Last of Us told an exciting, cinematic story, and its HBO adaptation is expanding on the post-apocalyptic setting. The centerpiece of Episode 1 was the 30-minute prologue scene, which showed Joel and his young daughter, Sarah, the day a massive fungal zombie outbreak began in Jakarta and quickly spread around the world.

But just how did this catastrophe begin? In the game, the answer was infected crops in South America, but eagle-eyed fans have spotted some conspicuous lines in the HBO series that may lead to a different answer.

Redditor anagnost suggests that the true origin of the outbreak lies in a common household substance: flour. The more you examine the prologue, the more this becomes obvious.

When the episode begins, Sarah greets Joel with a breakfast of eggs because they were out of pancake mix. Then, on their way out the door, their neighbor offers them some fresh biscuits. Joel politely refuses, saying he’s on the no-carb Atkins diet. That’s two encounters with flour — and the cordyceps — avoided, all while their neighbor pointedly serves a biscuit to the elderly Nana.

Later, when Sarah returns home from getting Joel’s watch fixed, she hangs out with the Adlers and helps Connie bake cookies. She doesn’t seem interested in eating any, however, because they have raisins. Meanwhile, Joel forgot to pick up a birthday cake after a late day on the job.

Being a slightly bumbling TV dad may have saved Joel’s life. After all, if the outbreak didn’t start with flour, then why is the script carefully engineered to highlight the fact that all the key characters managed to avoid it? And flour as a vector for illness isn’t unheard of — in 2019, for example, it was the source of an E. coli outbreak.

There’s more direct evidence too. In the post-episode podcast, co-creators Craig Mazin and Neil Druckmann mentioned the biscuits, then immediately told host Troy Baker that “careful viewers of this episode will be rewarded repeatedly because little bits of breadcrumbs have been planted that will pay off later in interesting ways.” Maybe the word choice was just a coincidence, but “breadcrumbs” is just too notable to not be considered a piece of evidence.

Still not convinced? We know the outbreak starts in Jakarta — Sarah reminds Tommy and Joel it’s the capital of Indonesia — and that just so happens to be the location of the world’s largest flour mill. If that’s not the perfect place for a contaminated sample to be shipped all over the world, what is?

The Last of Us Episode 1 is streaming on HBO Max.