 Why was the fuel drained out of Hennessy's ship's tank?
But something had happened to the exploration party fifteen years back, and to the more recent ship under Hennessy that was sent to check up. Even the deep gorge where they'd found Hennessy's carefully buried ship was completely hidden by the fog. Earth had ordered him to detour here, after leaving his load of deep-sleep stored colonists on Official World 71, to check on any sign of Hennessy. One, at the front, was stuttering into life, and Gwayne dashed for it as the exit port slid back. I want to know what happened to Hennessy and why that ship was buried against detection. We've scoured this planet by infra-red, and there was no sign of native villages or culture.
 Hennessy drained it so they couldn't leave
 Gwayne doesn't know  Hennessy drained it so they couldn't leave  it was destroyed by creatures from the planet  the blobs used it for energy