Halia hires a doppleganger to attack and kill the Adventurers

Halia feels its best to go to the Wave Echo Cave and gets a doppleganger to stay here in Cragmaw castle and follow the adventureres until they arrive. This is a precautionary way to prevent her from not knowing where they are. If the adventurers some how defeat King Grol then she will know and can leave the Wave Echo Cave.