The Serpent House by Davenport, Bea (2014) Paperback

The year is 1898. Twelve-year-old Annie, traumatised by her mother’s death, goes to live with her brother Tom, who works in the gardens at Hexer Hall. There, the mysterious Lady Hexer takes an interest in Annie and soon discovers that the child is able to travel back through time to the eleventh century, when the site of the Hall was a leper hospital, run by a strange doctor intent on using dark magic to cure his patients. Lady Hexer demands that Annie fetch back the doctor’s book of magical cures, guarded by fearsome serpents that terrify Annie. As Annie spends longer at the medieval hospital, she begins to realise that the doctor’s medicines may in fact be more curse than cure. Meanwhile, a creeping sickness engulfs Hexer Hall. Could the black magic of the past be seeping into the present?