Harry suspects that Scott Weston, the injured gunman, was shot by another person and it becomes obvious that two guns were used in the massacre. Scott's mother tells Dean Mears that Scott and Jason were good friends, Scott looking out for the more fragile Jason. Meanwhile Nikki is held prisoner in the deserted mortuary by unbalanced Neil Corrigan, who appears to have planned the massacre with Jason - who chickened out and killed himself - and then framed Scott. Ultimately video evidence reveals what actually happened, as well as locating the bomb.

Nikki and Harry are called to the Dutch Embassy in the wake of a gunman killing three people,including police constable Barlow and the brother of ambassador Van Buren,though the latter officially died three years earlier. Van Buren's son Jacob went missing fifteen years earlier and now his grandson Jack is missing, Jack's mother Klara and young policeman Whitehead being among the wounded. Curiously the CCTV cameras were switched off at the time of the shooting but,recovering in hospital,Klara claims the murderer was Jacob. The news coverage has a strange effect on telephonist Mary Olivant,who is found hanged,though Leo finds the death suspicious. He is also wary when another pathologist,Sabiston,whom he once trained,is called in to carry out the post mortems at the ambassador's request.

Mary Olivant turns out to have been the Van Buren's nanny at the time of Jacob's disappearance and a body unearthed near to where her corpse was found is identified as that of the little boy. Diederick Van Buren had been paying her thousands for years but she had recently seen Klara and told her the true fate of her brother. The so-called bodyguard was actually Diederick,allegedly working for MI6,and the pathologist who pronounced him dead three years earlier was Sabiston,working with Superintendant Mansfield in a cover-up on behalf of the embassy. Harry finds Jack,who has gone into hiding and who saw all that happened on the night of the shooting,for which reason he is protecting the killer.