The rising action is the part of the plot that leads to the climax. This section of the plot comes straight after the exposition, and takes the form of a series of events that ratchet up the tension and place the characters in a position of more and more danger as time goes by. We can therefore see that the rising action begins as David understands who he is and how special he is, and both he and his group of telepaths take steps to conceal their true identity. This of course becomes threatened more and more by the arrival of Petra and events such as the marriage of Ann, which threaten to reveal the telepath's secret to the very harsh and unforgiving society of which they are a part. Ultimately, the rising action ends with the climax of the novel, which is the confrontation in the Fringes between the mutants who have been expelled and the Waknukians and the arrival of the Sealanders.
The falling action comes after the climax and leads to the resolution of the novel. In this story we can therefore see that it consists of the face-to-face meeting of the telepaths with the woman from Sealand and Michael's choice to not travel back with them but to pursue love rather than safety.