The Thursday Syndrome

With a Thursday murder, DI John Hunter always expects something odd, but this one is a first. The dead woman was calling herself Rosalind Howard-Baker, but that is the name of a much older senior High Court judge who has disappeared from her home. Is the woman who she says she is? There is nothing in the apartment to confirm her identity, but the recent extensive facial surgery she had undergone has made her the spitting image of that judge as she appeared twenty years ago. John arranges to have Howard-Baker’s long time lover view the body. At first sight he is unsure, but other parts of her body convince him that the corpse is not her. They have a Jane Doe.
John receives a phone call from a man who claims he knows who killed not only that woman but most intriguingly who also murdered John’s foster mother, a Government spook, over twenty years before; a murder John would dearly love to solve. They meet, but the man is shot before he is able to speak.
He is identified as another spook and John is now sure that the two murders were committed by someone in MI5.
In that headquarters he is confronted with a hall of mirrors and a host of suspects but finally works out who the killer is.
He knows that if the man is arrested he will find a way to get off the hook.
John faces a dilemma. Is the only answer a final solution?