Death Comes of Age - 1, #4

After the trauma Sue experienced in "The Dark Eucharist", she and Alan decide to go down to Cornwall for a break to get away from it all.  However, Sue hasn't been feeling well for some time and as the holiday continues, she becomes decidedly worse.  Is there more to Sue's illness than meets the eye?  A young girl is found murdered on the beach and then Sue is abducted.  Who is behind Sue's abduction and is there any connection between that and the murder of the young girl?