Explore the cutting-edge world of borehole observatory networks in this AGU21 roundtable discussion. Delve into the science behind monitoring earthquake-generating faults from within subduction zones. Learn about the new network of observatories beneath the seafloor in Japan and New Zealand's "Pacific Ring of Fire" regions. Discover the latest insights into the earthquake cycle, including implications for hazard forecasting and slow slip events. Hear from expert panelists Demian Staffer and Laura Wallace as they discuss current findings and anticipate future breakthroughs in this field. Gain a comprehensive understanding of topics such as subduction zones, borehole instrumentation, data collection, slow slip modeling, and the challenges of undersea observatories. Examine case studies from the Hikurangi Subduction Zone and explore the potential for earthquake forecasting through advanced monitoring techniques.