What is the figurative meaning of "on a wire" in the following passage of The Great Gatsby that describes when Gatsby is going to see Daisy for the first time after five years of absence?
"With his hands still in his coat pockets he stalked by me into the hall, turned sharply as if he were on a wire and disappeared into the living room. It wasn’t a bit funny. Aware of the loud beating of my own heart I pulled the door to against the increasing rain."
Anxious and on edge about his reunion with Daisy at Nick's bungalow, Gatsby worries that she is not coming. Then, when Nick hears the motor of a car driven by Daisy's chauffeur, he goes outside and the nervous Gatsby slips out another door, as well. Of course, Nick is surprised that no one is in the living room when he escorts Daisy in. With a "light, dignified knocking" at his front door, Nick opens it to find a rain-drenched Gatsby "glaring tragically into my eyes." Nick becomes disconcerted himself as Gatsby "stalked" past him "as if he were on a wire." Here the simile is of Gatsby likened to a tightrope walker, who nervously balances himself. Further, he stands at the fireplace and knocks a "defunct" clock off the matelpiece, a symbol of the death of time for Gatsby, who has been haunted by the ghosts of his lost love for Daisy. Now, when she is in the living room, he is nervous like the tightrope walker who must balance himself in order to survive. Thus, Gatsby tries to set a balance between the past and the present.
When Daisy tells him in a "matter-of-fact" voice, Gatsby's "automatic quality" to his response that it has been "[F]ive years next November" indicates the magnified importance of this time to him that now has, at least temporarily, died away in his reunion with Daisy as he "tragically" attempts to recapture the past. Still figuratively walking a tightrope of emotion, Gatsby pulls Nick aside, saying,
"This is a terrible mistake..." shaking his head from side to side, "a terrible, terrible mistake."
This remark, of course, is foreshadowing of the tightrope walker's fall from the wire of his glorious delusions. Clearly, then, the simile of Gatsby's likeness to a man on a tightrope is an apt one as he strives to balance the past against the present.