Before Martin and Scholastic created a separate mystery spinoff series, the baby-sitters would sometimes channel their inner Nancy Drew in the main series. Nowhere does this work better than in The Ghost at Dawn's House, a spooky story replete with a secret passageway and a haunting peek into Stoneybrook's past. While Dawn stories typically focussed on either her passion for the planet or issues with her parents, The Ghost at Dawn's House is a more lighthearted tale — and it's all the better for it.