This summary is in no way intended as a substitute for viewing this fabulous episode.
Sir Reginald Walker enters the head office of his company, Empire & European Foods, and makes his way to the 18th floor. In the Chair of a special board meeting, he tells the members that the minutes will be deposited with the company's solicitors as there may come a time after the war when there will be a need to demonstrate that there was a consensus on the company's European operations. Only selected members are in attendance - those "in tune" with Sir Reginald's thinking. The business to be discussed is to be kept secret. Philby, one of the directors, looks distinctly uncomfortable. Sir Reginald's son, Simon, has just returned from Switzerland. He shows a letter that confirms an agreement that will make Empire & European Foods the largest processor of non-mineral fats and oils in Europe, both during and after the war. "It doesn't even matter who wins - we can't lose."
After the meeting, the secretary, Agnes Browne, makes a phone call, reporting the existence of the letter and arranging to hand it over. She is next seen plummeting from the 18th storey window.
DCS Foyle listens in court to his sergeant giving evidence in a case of murder which the defence claims to have been suicide. Leaving afterwards, Milner concludes that Stephen Beck, the defence counsel, made a fool of him, but Foyle disagrees. The case is to continue. Beck meets the pair on the stairs and Milner is surprised to discover that the man, who is German, and his boss are friends. Foyle and Beck arrange to go fishing at the weekend after discussing the amount of food in the shops.
Sergeant Rivers is attending to four small children at the station desk when Foyle and Sam arrive. The children are collecting recyclable materials for the war effort. Foyle apologises for having again forgotten to bring his newspapers in for them and they agree to come back the next day. "That's the second salvage collection I've missed. They've got me down as a fifth columnist."
Lucy Markham and her brother Harry work Greenwood Farm on land owned by Walker. After tending a beehive on the farm, Lucy goes into the house and has a conversation with her brother about their financial situation. Harry has served time for breaking and entering and Lucy warns him not to go back to his old ways.
Foyle has been appointed to be referee in forthcoming war games in the woods around Hastings for the purposes of training the Home Guard; the regular army will participate. He attends a briefing given by the pompous Home Guard CO, Brigadier Harcourt. Philby, who is a Home Guard officer and the CO's second in command, explains that part of the exercises will be held on the Walker estate.
The brigadier is displeased when Foyle questions the way in which the exercises are to proceed and slaps him down. "You're here as a referee, Mr Foyle. I think you can leave the military planning to me." The leader of the regular army contingent, Captain Jack Devlin, arrives. He is already known to the DCS as he was Foyle's sergeant before joining up. Devlin greets his old boss cheerily and Foyle smiles in acknowledgement, but he is a little guarded. Outside the building, the two talk.
"They didn't let you transfer then? I heard a rumour that you were going to work with General Ismay."
"No, it didn't work out."
"You're damn good at your job."
"Well, if that's the case, what am I still doing here, I wonder."
Stephen Beck waits until Lucy leaves the farm and then approaches Harry. As Markham's defence counsel, Beck had succeeded in securing a greatly reduced sentence for the man's crime and now requests a favour in return - a theft of something from Greenwood Hall, the home of Sir Reginald Walker. Markham is very reluctant, but agrees. As Lucy returns home she sees a man leave and, on entering the house, notices Harry putting a piece of paper inside a book.
Walker's second wife finds her stepson locking the door of the cellar in their home. When she asks why, he explains that there are valuable vintage wines stored there. There is obviously no love lost between the two.
That night, Markham breaks into Greenwood Hall after drugging the two guard dogs. As he cracks open the safe, the sound wakes Mrs Walker who alerts her husband. Markham looks briefly at a document written in German that he finds in the safe, but replaces it and removes a gold box. As he makes his escape back across the grounds Simon fires a shotgun at him.
Next morning as Sam drives Foyle and Milner to Greenwood Hall, Milner says the break-in was reported by a warden on his way home who saw someone climb over the wall, but had not been reported by the householder. Interviewed about the incident, the Walkers explain that they didn't want to bother the police who already had enough to do and there was nothing taken because the intruder was chased off . It is noted that the safe is of a kind that would take a professional to crack. Simon Walker admits to firing a shotgun, but only into the air as a warning.
Outside the house, Foyle comments to Milner, "I've never met anyone quite so cheerful about being burgled." He says Markham could break such a safe and that the man came out of prison two months ago; it was Devlin's arrest before he joined up. Inside the house, Walker tells his son that the culprit must be found and to contact someone he knows within the police force. Mrs Walker does not understand why her husband did not report the break-in; she does not know that anything was taken.
Lucy discovers that Harry has been house-breaking again when she sees shotgun pellets in his shoulder. She treats his wounds. He tells her he was doing someone a favour. He was not going to steal anything for himself, but had found something worth a fortune. He will not tell her what it is.
That evening, Beck, fishing with Foyle on the edge of the river (see under Skues), comments on he and his wife leaving their country in 1935 when they saw what was coming. About England, he says, "There are things about his country I would always miss if I had to leave." Foyle wonders at the way he says it.
Markham meets Beck at the court the next morning. He tells him that he took nothing from the house and didn't have time even to open the safe. Beck does not believe it and threatens him, but Markham says nothing.
Sam calls into Foyle's office to report that there has been another break-in and ask him to have a word with the culprits who are at the front desk. Two of the children who had been collecting paper have broken into their school hunting for salvage - they know exactly what items can be reused for the war effort. Foyle tells them that their little group must stick to collecting paper only and they need a new commanding officer to keep them out of trouble. He glances mischievously at Sam who is standing behind him. "Captain Stewart, you've just been promoted. Keep an eye on 'em!" and walks off before she can protest.
Milner goes to Greenwood Farm to find Harry, but his sister tells him that he is in the Home Guard and involved in the exercises shortly to take place. Milner spots a blood-stained shirt in an open waste-bin and Lucy explains that her brother cut his hand on a fence.
Connor and Clarke, two members of the Home Guard, talk in a pub about the incident at Greenwood Hall. Criminal associates of Markham, they assume him to have been responsible and resent him working on "our patch" without them. They decide to sort him out during the war games.
The Walkers' police contact give them Markham's name as a local man capable of cracking their safe.
Beck plays the organ in the local church. (He is playing the section of Cantata 147 known as Jesu, Joy of Man's Desiring; J.S. Bach) He is there when approached by a Miss Pierce who tells him that he must leave in three days. He replies that he cannot leave yet because he is in the middle of something. She mentions the death of Walker's secretary, saying that she understands that Beck feels responsible, but he is disobeying orders.
Sam marches her four small charges, pushing their load of collected paper in a baby's pram, to where they can tuck into a reward of lemonade and buns. She joins them.
Captain Devlin calls at the police station to collect Foyle for the exercises. On the way, they discuss Harry Markham. Devlin is disgusted with the lightness of the three-month sentence Markham received. He is angry that some men commit crime while others fight for their country. "People like Markham should be shot."
In the hall where the war games are being organised, the brigadier tells Philby to assign men to keep the public away because there is live ammunition about. Simon Walker comes in and is seen by Foyle. Walker is surprised to see the DCS but approaches him as though having been looking for him. He mumbles something about realising that they should have reported the break-in and wanting to apologise for not having done so.
Out on the field, Connor and Clarke catch up with Markham. They want a share of what he took from the house and when he denies any theft, they attack him. Philby interrupts and orders them to join the others. As they do, Connor warns Markham to look out because it is very lonely in the woods and there is a lot of live ammunition around.
The exercises begin. Philby briefs his HG group and assigns Markham to guard duty in the lower wood.
There is tension between Walker and his wife who is unhappy to be in Hastings and feels that her husband and stepson are keeping things from her.
Philby notices that Connor and Clarke are no longer with his group, but assumes they are just trailing behind. He leads his men toward their position, but Devlin's regular soldiers appear, take them all prisoner and order them to remove their uniforms.