Question

how is grandpa able to know the truth

Answer 1

Grand father came to know about all the happenings when he came downstairs and all were scared and anxious. Amelia to save herself she only tells the truth of Elizabeth that he had promised the gold watch to Jimmy. Elizabeth to save herself she told that amelia had taken your bureau and slippers. When    

grand father hear all this he felt sad . So by this grand father came to know about all happenings