Becky Driscoll as a Symbol
Becky is a symbol of happier times in Miles' life, and this is initially the reason that he enjoys her company. She symbolizes the time before his divorce when his life was simpler and as they were briefly dating she also symbolizes a certain naïveté about relationships and love before hurt and failure came in. Becky also symbolizes absolute trust; she was by his side in their teenage years and so is absolutely trustworthy in a way that nobody else around him can be.
Lack of Fingerprints as a Symbol
The lack of fingerprints symbolizes a non-humanness that is the only physical manifestation of the alien form. When Jack brings Miles to view the dead body on his billiard table, it is impossible for Miles to tell that it is not human; the lack of fingerprints however confirms this, and subsequently comes to symbolize a "snatched body."
Lack of Emotion as a Symbol
The lack of emotion when remembering things that previously brought about the demonstration of total joy, sadness or other strong feelings is a symbol of a "person" being other than the person they are purporting to be. The lack of emotion symbolizes a lack of humanity and also symbolizes alien invasion of the original person in some way.
Humanizing of the Alien Form as a Symbol
Professor Budulong believes that man's inability to conceive of anything outside of his own experience is symbolized by the human imagination of an alien form which is basically a human form with distorted features, misshapen limbs and green-tinted skin. Because it is outside the human realm of experience to picture an invading alien force as a large seed pod containing dust matter, the human brain either rejects, or does not even imagine, this concept. The fact that humans imagine alien life to have a human type body with four limbs, and a head containing something akin to the human brain that thinks the same kind of thoughts as a human is seen to be a symbol of man's lack of imagination andasymbol of the failure of the human brain to think in any way that is not empirical.
Invasion from Outer Space as a Motif
The motif of invasion from outer space is a constant motif throughout the novel. The concept of extra terrestrial life coming to earth with the intent to take it over is discussed at length by Miles and his allies because they cannot imagine any other reason for such an invasion. They initially believe the invading life forms are the faceless human-like creatures that metamorphose into specific people and for this reason do not notice the gray dust that is present on the billiard table after "Jack" is destroyed, or in the closet after the would-be "Becky" fails to change into the real Becky whilst she is asleep. As the novel progresses, they realize that the dust is contained in the giant seed pods that fell mysteriously to earth and subsequently manage to identify the pods themselves as the extra terrestrial life.
