Commander Strax, Madam Vastra and Jenny arrive in the Victorian community of Sweetville in Yorkshire to investigate a series of grisly murders where the victims are found covered in a bright red waxy substance and also discover What has happened to The Doctor (Matt Smith) who may be if some kind of ttouble. Jenny meanwhile manages to infiltrate a sinister factory which is not what it seems and discovers something strange going on and also meets the sinister Winnifred Gillyflower (Dame Diana Rigg) and tries to find out about the elusive Mister Sweet, after whom the community is named. Jenny then discovers that Mrs Gillyflower is hiding a secret and has a villainous scheme known as the Great work and pretty soon they all find themselves in great danger, luckily the Doctor then finds help coming from an unlikely ally.
Meanwhile Clara’s charges discover some very old photographs featuring a person who looks alarmingly similar to Clara and begin to suspect that there is more to her than meets the eye and that she may have been to some very intersting places and times