At the Endeavour Segment of the Juan de Fuca Ridge, the motions of the tectonics plates and the rocks, fluids and organisms are all intimately connected in ways we do not fully understand. During this expedition, we will learn more about how the interaction between rocks and fluids supports life on and within the seafloor. In particular, we will collect microbes that live at extremely hot temperatures in the walls of the black smoker chimneys. We will recover and redeploy seismometers, instruments that have been left on the seafloor for the past year to collect earthquake data. We will sample fluids and gases from the hydrothermal vents to better understand the systems that drive the underwater hot springs of the Juan de Fuca Ridge.