'The girls at Maddy’s new school look through her as if she is invisible, and say mean things behind her back. The only person who has tried to talk to her is Gareth, who is new too. And he’s good at maths. Talking to him would mean social death. But then strange things happen in old inner-city terrace house Maddy’s family has moved into. She hears spooky noises on the stairs and sees strange faces in the mirror – first a ghastly white face, then a girl in a weird old-fashioned dress. They’re ghosts! The house is haunted!
'The girl in the mirror – Clarissa – starts to talk to Maddy. Maddy’s bedroom was Clarissa’s room back in the 1890s, and it’s the same mirror on the wall – though Clarissa is a Young Lady, so she has to call it a Looking Glass. The spook on the stairs is Clarissa’s brother Bertie, who died of whooping cough when he was six years old. Clarissa and Maddy get on really well – but then Clarissa disappears, and Maddy has strange visions of a huge, evil thing like a giant spider looming over her.
'Maddy’s baby brother gets seriously ill with whooping cough. Even in the hospital, the doctors are helpless.
'Meanwhile, back in the 1890s, the girl in the mirror is having problems of her own. Clarissa’s mother has been in a decline since Clarissa’s poisonous Aunt Lily was widowed, and she moved into their house. Aunt Lily makes a Strengthening Tonic for Mother every week, from plants in the garden. But what if the Tonic that Aunt Lily makes for Clarissa’s mother is actually making her sicker? What if she wants to get Clarissa’s mother out of the way forever? The two girls have to use all their intelligence and verve to fight against Aunt Lily’s plots, each in her own time, with help from Clarissa’s ghostly brother Bertie—but will they succeed?'
Source: Publisher's blurb.