Water's Secret

In a world where humans can gain control over one of the six elements, Valina is a particularly useless and lazy water elemental. She has spent her life drifting from place to place without a plan, until one day she gets a message congratulating her for passing a job interview.
The job is not one she ever applied for, nor is she given any information about what she is needed for. All she is told is that someone will pick her up, and she must from now on live in the designated house.
Valina becomes the sixth elemental living in that house, and soon learns that she's not welcome there. As she keeps her head down to avoid getting in the way, she must learn what her purpose is, and why someone as weak as her was chosen.
The more she learns, the more Valina realises that her acceptance wasn't down to luck, or a mistake. In order to find her place in the team, she must work out the water's secret.