Everyone believed that the mysterious plague which surfaced on board the huge oceangoing habitat Sea Venture had been stopped dead in the middle of the ocean. Nobody reckoned with Julie Prescott's unborn baby —nobody even thought about whether pregnant women could bring the parasite back to shore.

Julie herself didn't reckon with what kind of man she'd fallen in love with. John Stevens wasn't your average guy, despite how he seemed. In fact, he was a highly-skilled assassin.

McNulty's disease, as the alien plague came to be called, changed his life and his values —but didn't take away any of his skills.

When McNulty's symptoms started showing up in the population on land, panic ensued. Though McNulty's was not fatal, and recovering patients showed no ill effects, scientific and popular opinion feared that too little was known and the disease must be curbed at all cost. A concentration camp of all McNulty's survivors would be set up —and where better than on the Sea Venture itself?

But John Stevens wasn't the kind of man to let his family be imprisoned...

In The Observers , Damon Knight has skillfully combined a gripping tale of suspense with a thoughtful examination of contemporary social values.

2nd in the CV series from Damon Knight, a SFWA Grand Master.