midnight
As the girls literally shivered , following the exclamation of Grace -- shivered as much from the chilling rain as from the terror induced -- Amy said , with such a queer intonation : `` Do you suppose that door opened itself to invite us in ? '' There was a moment of silence . Then Grace giggled , Betty caught her breath in a gasp , Mollie went into a perfect gale of laughter , and Cousin Jane -- well , she said it herself afterward -- she snickered . `` Amy , that 's the most sensible thing I 've heard since this series of midnight adventures began , '' declared Mollie . `` And since the door did open to let us in , suppose we take advantage of it , '' suggested Betty , `` and go in . '' `` What -- into the -- the haunted house ! '' and Grace 's voice was shrill .