The book is about this brother and sister that wake up in their beds and discover they have woken up in their house but older looking without anyone able to see or hear them. They go on to help these ghosts living in their house against their evil aunt, who can occasionally sense the main characters. I remember a small joke about the little brother not knowing what a minor was and mistook it for a miner in an inheritance letter or something. In the end (spoilers) it is discovered that the main characters were ghosts all along and died falling into a frozen lake together and the Evil Aunt just liked vintage furniture.
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