"Shall we meet the Queen? "

Peter Warmington returns to England after a long spell teaching at a university in South America. Immediately upon his return, he spots an old acquaintance called Juan whom he enthusiastically invites back to his new flat. Unfortunately, he has no inkling that his "friend" is actually a terrorist, who quickly murders his host and assumes his identity in order to carry out a political assassination.

But Juan himself does not realise that Warmington's 10 year old daughter is en route to London to spend her holidays with the father she has never seen. When Rachel arrives at the train station, the transit police become concerned when no-one seems to have arrived to collect her. They take her under their wing and send an officer round to her father's flat to investigate.

Taken by surprise, Juan manages to bluff his way through the resultant questions when he arrives to collect his "daughter" from the station. Fortunately for him, Rachel does not suspect anything and the only photograph she has of her father is too indistinct to be of any use. Although slightly uneasy about the whole business, the police hand over Rachel to Juan but - as the sergeant asks a constable as they are leaving - "Why did he take his glasses off to look at the photo..?"

Arriving back at the flat, Juan introduces Rachel to her "stepmother" Aiyako - in fact another terrorist. Aiyako and another member of the organisation, Hassel, want the girl killed but Juan manages to convince them to continue with the deception as he believes that Rachel is an asset to their mission. The object of that mission soon becomes clear when Juan cheerfully asks the girl "We've been invited to a royal garden party, Rachel...would you like to go?"

As preparations for their mission move into full gear, an unexpected complication arises when, appalled, Rachel finds the body of her dead father in the linen closet. Uncertain of who the man is, she manages to leave behind a message for the police when Juan takes her to have a dress fitted for the party. Attempting an escape, she is caught by Juan and taken back to the flat where the three agree that she must be killed after the mission has been completed. However a fourth member, Wormald, disagrees strongly and virtually blackmails the others into allowing him to take Rachel back to her home in Scotland afterwards. Caught in a bind, the "organisation" agrees and Wormald spends a fearful night alone in hiding.

As time slips away, the little girl's message is discovered by the police...but it already may be too late, as Rachel, Juan and Aiyako arrive at the royal reception, invitations in hand, ready to meet the Queen...