“Very enlightening,” said Holmes. “And what did the authorities do as a result of this claim?”

“Nothing, apparently. Harker had already been demobbed at that point and was residing somewhere in Holland. I imagine the War Office had more pressing concerns to deal with, so let the matter rest there.”

“And what of Harker after the war? Do you have anything more you can tell us about that?”

Wattisfield flicked forward in his notebook. “Only a few bits and pieces which Mr and Mrs Dawson shared with me, based on their conversations with the Harkers. They understood that after the war, Harker had continued to live in the Dutch town of Giethoorn in the Eastern Province of Overrijssel, where he married a local girl called Katerina. In 1920, their son Gerald was born. Harker was said to be well regarded in the town, making a modest living as a gem dealer. A year later, he bought Trimingham Manor and moved the family to England. He continued to have a number of business ventures in Holland and beyond, including a controlling interest in some diamond mines in South Africa. Earlier this year, he and Katerina had been invited to tour one of the newly-opened mines in the Archaean Witwatersrand Basin. As they did so, a pocket of trapped gas was ignited by a miner’s candle lamp and the explosion ripped through the mineshaft, trapping the touring party and killing the couple. As the appointed executor of their legal and financial affairs, Barrington Henshaw took charge of everything from that point on.”

“I must commend you for your thoroughness, Chief Inspector. That you have managed to ascertain all of that background information in just a few short hours is indeed testament to your professionalism,” observed my friend.

“Thank you, Mr Holmes, but I fear it has done little to help me solve this particular mystery. I am still no closer to understanding why Heinz Descartes may have attacked Henshaw or, indeed, what any of this has to do with the money in the safe.”

Holmes smiled at the detective. “I may have a few more observations to add to our existing knowledge. And, unless I am very much mistaken, young Curtis is about to re-join us and tell us all about his findings.”

The footsteps from the hallway drew nearer and PC Curtis entered the study a couple of seconds later. He was red in the face and a thin sheen of sweat clung to his forehead - clearly not the sort of day to be running around in a heavy police uniform. “As you rightly guessed, Mr Holmes, there is a car parked in a clearing among some elms which back on to the fence at the rear of the estate. The new-style tax disk gave no hint as to the car’s owner, but on the front passenger seat were some papers, headed up with the words ‘Henshaw Legal Services’.”

“Capital! I will forgive you for your suggestion that I merely guessed at the location of the car, PC Curtis, when it was in many ways the only feasible explanation for what had happened to Henshaw’s vehicle, but then I digress. I was about to share some other observations on what occurred within this house earlier today.”

PC Curtis looked suitably admonished, but when I cast a glance in Wattisfield’s direction, I saw him give the young officer a sly wink of approval. Holmes seemed not to notice and carried on with his deliberations.

“Heinz Descartes had already informed Henshaw that he was to take a walk around the estate after his cooked breakfast. Having left Henshaw at the dining table, he returned briefly to his room, to pick up his rucksack and, no doubt, a few provisions for his hike. I think it unlikely that he would have taken the rucksack down to breakfast with him. Having collected this, he then left the manor and began to walk off down the drive. However, he retraced his steps back to the house only a short while later, perhaps to retrieve something he had forgotten or to spy on the movements of Henshaw. Either way, Mrs Dawson was not wrong in her assertion that Descartes had left the house twice this morning. For his part, I imagine Henshaw had left the breakfast table as soon as Descartes was out of earshot and had made for the study, fully intent on emptying the money from the safe, while all of the other occupants were busy.”

“What motive do you imagine he had for taking the money, Mr Holmes, was it just greed - a simple matter of theft?” asked Wattisfield.

“In this case, I believe it was simply that, Chief Inspector. With his impending wedding to the wealthy socialite, Verity Ainsworth, we can surmise only that he needed to supplement his solicitor’s salary with some extra funds. However, I am certain that he was the only person alive who knew the cash was in the hidden safe - it was originally a nest egg of Harker’s. In the reading of the will, there was no mention of the extra cash, which makes me believe that Harker had been content for the money to be secreted in the safe for some purpose other than the general maintenance of his family or the running of the estate. With Harker dead, Henshaw hoped to take the money for his own purposes.”

“If that was the case, why did Henshaw not take the money earlier, Holmes,” I enquired.

“A good question. But this is where our friend Descartes comes into the story. I am inclined to believe that it was no accident that the German arrived at Trimingham Manor looking for work soon after the Harkers had died. A search of his room a little later should confirm my thoughts on that. For the moment, let us assume that with the unexpected arrival of Mr Descartes, Henshaw was forced to put his plans on hold, until he could find a suitable opportunity to retrieve the money from the safe.”

“So, are you saying that Descartes knew about the money then, Mr Holmes?” asked Curtis, clearly keen to make sense of the story as we all were. “It’s just that I thought you said earlier that only Henshaw knew about the contents of the safe.”

“Yes, Curtis. I am certain that Descartes knew about the money, he just didn’t know where it was. Only Henshaw knew about the hidden safe and he retained the key to open it. Descartes cannot have been immune to the fact that no one other than the solicitor was allowed in the room. Perhaps that is why he came back to the manor, to see what Henshaw was up to.”

Wattisfield was the next to comment. “Working along the lines of your theory then, Mr Holmes, we have Descartes returning to the house and catching Henshaw in the act of taking the money from the safe. An altercation then takes place as a result of this, and Henshaw is either pushed, or falls back accidently, against the mantelpiece...”

“Quite so, my friend. We are indeed fortunate that Henshaw took to keeping the door of the study locked and the room out of reach of Mrs Dawson and her excellent cleaning regime - I have rarely seen a more pristinely maintained domestic interior than the area outside of this room. But, with the curtains opened up a fraction, you will observe that we have a revealing layer of fine dust on all of the furniture surfaces. Look closely at the desk top and you will discern that we have preserved a small record of what occurred between Descartes and Henshaw in the moments before the latter’s demise.”

Holmes then walked around the desk and positioned himself to one side of the heavy oak bureau, with the fireplace behind him. “Henshaw would have stood somewhere around here. And as Descartes moved towards him, or wrestled with him, we can see how Henshaw’s hand swept back over the desktop leaving a distinct trail in the dust. The fingerprints at the edge of the desk are where he tried in vain to cling to the woodwork before falling backwards.”

Wattisfield continued to look unconvinced: “So, Descartes then makes off from the scene, carrying only the possessions he has with him. There is, of course, one obvious flaw in this imagined chain of events...”

“And that is, Chief Inspector?”