Readable enough, but I found this very uneven. It starts with our hero leaving Earth, against the wishes of his girlfriend, in a scene not bad by 1970s standards, but unconvincing. Then many chapters of interpersonal tensions and hidden agendas on the moon colony preparing to launch a fleet of robot-run ships -- called forts -- to attack a large incoming alien vessel detected at the edge of the solar system. Just when I thought we'd never leave the moon, our hero flies to join the fleet, bringing along the one remaining prototype robot that might be smart enough to save the day. At no point is there any discussion about the wisdom of attacking without provocation. No spoilers here on what happens when our hero meets the aliens, but I had trouble keeping my disbelief suspended.

OK but for a story set on the moon, too much of the plot was Earthbound for me, just as old science fiction movie serials always seem to end up being just good guys punching bad guys, but on Jupiter. A sign of its times is when the main character enters the lab where he is to work on the moon, and sees "three men and a girl". ( )

This is a nice low-key tension thriller. Humanity is on the edge of extinction when a titanic ship starts it's deceleration burn into the Solar System. The last paranoid leaders dragoon a lone scientist into using his autonomous 'golems' to send a scout to determine if the ship is hostile. ( )