More Fight Scenes En Route To Jupiter

Continued from the previous post:

Banning activates fire extinguishers so that Gentry must struggle with plastifoam lather;

Banning and his two companions join first mate Tetsuo Tokugawa, who is from Luna, on the bridge;

monitoring key points on a screen, Banning sees one of the two stewards, Tietjens, dead from a shot to the head;

next he sees, in the engine room, Professor Gomez, a passenger en route to the University of X on Ganymede;

Gomez, claiming to have killed another crew member called O'Farrell, says that he and his associates are taking over the ship and have already taken prisoner everyone except the four on the bridge and that Banning had killed Falken;

however, Gomez refuses to divulge their purpose so we are still no wiser;

breaking off contact with Gomez, Banning discloses in conversation on the bridge that the prisoners must be another steward, two engineers and a deckhand;

on Banning's order, Tokugawa stops the ship's spin;

leaving Wayne and Cleonie on the bridge, Banning and Tokugawa set off to fight Gomez and co.

So who is on the ship?

Captain Banning;
Engineer Devon;
Andreyev;
Cleonie;
Falken (dead);
Gentry;
second mate Wayne;
first mate Togugawa;
Gomez;
steward Tietjens (dead);
O'Farrell (dead);
a second steward;
two engineers;
a deckhand.

That does add up to the fifteen mentioned by Devon. But what it is all about we still have no idea.