I chose a theme of media image versus reality. I wanted to juxtapose the stalker's obsession and subsequent disillusionment with the radio personality's image against the stalkee's temporary enjoyment of "celeb" status in attracting a stalker. The situation then turns sour. Disillusioned by the gap between the real Lily and her image, the stalker tries to destroy the image by circulating false stories in the media to discredit her. This backfires and attracts public sympathy for Lily.
Rather than sex, I wanted obsession and power as the primary motives. What were the most personally invasive things a stalker could take? Underpants had sexual connotations. A toothbrush seemed more appropriate for a personal invasion that was nonsexual in nature.
A stalker would demonstrate power through complicating the stalkee's life: changing appointment times or leaving false voice-mail. Changing locks or taking computer back-ups and crashing computer data offered other possibilities. I structured these complications in order of the impact they'd have on my character.
Concentrating the timeframe of my story intensified suspense. Using first person from Lily's viewpoint exacerbated the tension. I wondered whether to insert a second viewpoint, perhaps in italics, to take the reader into the stalker's motivation.
I considered suspects: Radio panel operator? Housemate? Why weren't Lily's parents around? How old was Lily? What did she look like? Because I was writing for the young adult market, Lily needed to be 17-18. The midnight-to-dawn shift at the radio station attracted more odd minds, but would a station put a seventeen-year-old on the air at that hour?
I didn't want a violent death, but the ending had to have emotional credibility. Maybe the stalker destroyed Lily's image rather than the real person. On the one hand, a disillusioned disciple destroys his guru's image; on the other, an obsessive groupie has to face a less-than-perfect idol. This scenario made for a viable climax. And then I added a twist!
Thanks, hate-mailer, for the motivation to write this novel.