Cobra is the first of a three-book series. Cobra Strike (1986) tells of the danger-filled exploration of neighboring planets a generation later. Jonny, now a distinguished but ailing former governor, leads a survey mission to uninhabited planets. His sons Joshua and Justin — the latter also a Cobra — investigate the secretive human inhabitants and strange ecology of Qasama.

In Cobra Bargain (1988), Justin's daughter Jasmine becomes the first female Cobra. As the sole survivor of a shuttle which crashes on Qasama, her skills and bravery expose an alliance threatening both that planet and her home world.

Cobras Two (1992) is a reprint of Cobra and Cobra Strike, published together in one volume.