This could go one of two possible ways, and I'm hoping to play out at least one of these two ideas here.
1. On holiday either in the US or Europe, I'm lured into a fetish/bdsm shop, and talked into trying on a collar, armbinder, hood and gag, with more items following, with the shop owner deciding to keep me as the shops newest unwilling model, and for their own pleasure.
2. While travelling, I decide to do something different, and visit and bdsm dungeon. Mid way through, the owner decides that I'm just too good to let go, and keeps me as the dungeons new unwilling slavegirl there.