Xenation: Draw the Line — Lazette Gifford

When humans found an abandoned -- and ancient -- space station, they moved in to study the place they called Xeno-Station and later shortened to Xenation. Following them came three other races, all intent on learning secrets hidden in the sealed areas of the station. Only now one of the humans has a dangerous link to the heart and controls of this alien place, and he's learning there are secrets and dangers no one imagined.