Idea one. I'm the youngest CEO ever of a major corporation, but love to go to a private bdsm club and submit. Someone in the company finds out, who covets my job, and has me sold to a dominant that they know, ensuring that I disappear, kept as his or her slavegirl, maid, kept while someone else heads the company, but could visit regularly to remind me of what I had, and what I've now lost.
Idea two. New to a city, I go out with some new friends to a new bdsm club. Buying a drink, I have no idea that its laced, and wake up in a latex catsuit, ballet boots, armbinder, hood, gag and collar, to be sold.
Idea three. My boyfriend and I, holidaying in a foreign city, play a game, pretending to be a prostitute and client. Yet I'm arrested and held with several other girls who were also picked up. The girls pimp, coming in to get them out, sees me and gets me out with them, only he intends to keep me.