A groundbreaking study published in *Science* on May 14 reveals a thriving community of protist-dominated fauna in Oceania's hadal zone, which includes ocean trenches that plunge from 6,000 m to nearly 11,000 m. Led by the Institute of Deep-Sea Science and Engineering (IDSSE) of the Chinese Academy of Sciences, this research highlights a previously unrecognized carbon hotspot, where sessile foraminifera contribute 2–11% of total eukaryotic biomass carbon in these trenches. The study identified 32 species across six phyla, many of which are new to science, including a new family of foraminifera (Plumettidae) and a new family of bryozoans (Pierrellidae). The fauna, primarily composed of agglutinated foraminifera, reaches densities up to 4,300 individuals per dm2. Notably, the organisms were found to have a heterotrophic diet, challenging previous assumptions about their energy sources. The research also extends the maximum depth records for several marine taxa, suggesting that the hadal zone may serve as a refuge for ancient lineages. This study not only sheds light on the biodiversity of deep-sea ecosystems but also emphasizes their significant role in global carbon cycling.