I set the impellers in cautious forward drive and drifted towards the massive, curving wall of the hull. Inside the helmet, simulation graphics awoke on the surface of the visor and I saw the entry points Irene Elliott had found for me delineated in red. One in particular, the unsealed mouth of a disused sampling turret, was pulsing on and off next to fine green lettering that spelled Prospect One. I rose steadily upward to meet it.