 Which of these is not a reason Russell killed Dunbar?
Four men, thought Russell, held together by an invisible string of gravity, plunging through a lost pocket of hell's dark where there had never been any sound or life, with old Dunbar the first in line, taking the lead because he was older and knew where he was and where he was going. Russell had no idea now how long the four of them had been plunging toward the red-rimmed sun that never seemed to get any nearer. When the four of them had escaped from that prison colony on a sizzling hot asteroid rock in the Ronlwhyn system, that wasn't enough for Dunbar.
 He wanted his ration supply
 The time in space was driving him nuts  He wanted it to be more quiet  He thought it would be the only way to go the right direction  He wanted his ration supply