Blood Nexus follows three generations of Earthlings. The first makes contact with apparently friendly aliens. The next two generations help the aliens expand their control of other star systems. To receive the benefits of the aliens' advanced technology one must have their blood tested once a month. The next two protagonists come in contact with five different planets: one created by the aliens for spiritual training, one desert planet, one planet where genetically engineered beings are destroyed for blood, and two planets controlled by hostile aliens.