When Tracy Brigden is murdered in the privacy of her own home, does the murderer realise that he has been seen through the window. Is the only eye witness safe and can they lead Police to the murderer. Alarm Bells ring for Maggie, Tracy's sister when Tracy doesn't return her calls and then fails to meet her at the railway station, as previously arranged. It isn't like Tracy. This has never happened before as the sisters are quite close. As Maggie arrives at Tracy's the mystery deepens and a worried Maggie soon calls the Police.