The door.

When she steps back down into the living room, Vanessa freezes, as she hears a sound coming from the front door.
Somenone seems to be fiddling with the lock, and before the girl could even realize what's happening, opens it.

Startled, Vanessa turns towards the hallway, but too surprised and scared to move a muscle, she just stands there in her skimpy bikini and filp flops as the steps draw closer.

"Hey Vanessa! It's been so long since the last time isn't it?" Says the voice from the doorway.