For decades, the story of Parkinson's disease has been written in proteins large enough to see — but a team of researchers has now found a hidden chapter, written in structures so small they eluded the field's standard tools entirely. Using single-molecule imaging sensitive to nanometer-scale structures, they detected phosphorylated tau aggregates in brain regions that conventional staining declared nearly clean, with the heaviest burden falling on those who had also lost their minds to dementia. The discovery, drawn from post-mortem tissue across 29 donors, does not overturn what we know abou