Jim Cowen working on the in situ filtration system (McLane) that will be mounted on the major instrument sled. This system must be carefully cleaned, equipped with various working filters and then primed (all interior volumes must be filled with sterile seawater) prior to deployment (this night). This system will be in-line with our in situ electrochemical analyzer and will remove particles (including microorganisms) from fluids from basement rock buried under hundreds of meters of sediments.