Thriller film narrative (Hide and Seek)

Beginning:
        The film opens with a flashback of the girls past, their childhood. The five girls are having a sleepover party and during the sleepover one the girls suggests to hide from their friend while she's gone to get a drink. This then turns into a game of Hide and Seek. One the of the girls is killed during the game by a mystery killer/ stalker.

Middle:
        The girls are now all grown up and are living separate lives. They start coincidentally bumping into each other. One of the girls is having a wedding and arranges a hen party. A couple of days before the hen party strange things start to happen to them. For example one girl will wash her hands and blood will run from the taps, instead of water. Another might be seeing their dead dead friend in the mirror. The girls start to disappear one by one, is this the mystery killer? They are killed by strange happenings. The audience are left left wondering and in suspense.

End:
        We don't actually find out who the killer is, we are left to think, we only see a hint of his identity; a possible action to symbolise the killer for example, a hand grip.