In the previous episode Holmes and Dr. Watson received an exotic visitor for coffee. Dr. Tinder, an alias for the recently coronated young Sultan of Suwat, brought with him a Diplomacy map and a mysterious note for a romantic rendez-vous with a smart young lady that he had met in Paris. To see her again he would have to catch a train in a fortnight, departing at 17:34 from one city in Europe and bound to another, that were the locations of two army units, one from Paris, one from London, on the accompanying map. There was just one tiny problem: There were no units on the map, only supply centers in various colors. What could this mean?

The three of us looked together at the map. Holmes took a sip of his Turkish coffee, then looked up at me. "Watson, where are my manners? Let me make you a cup. Sugar?"

"No, really, Holmes, you don't need to. My stomach has never quite accustomed itself to the oriental taste, not since my days in Afghanistan as an army doctor. I'll be quite alright with an espresso, black."

"Even an oriental like me appreciates an Italian espresso from time to time," Sir Warwick Tinder, a.k.a. the Sultan of Suwati, remarked. "Although I prefer it the oriental way, lots of sugar."

"An oriental espresso," Holmes quipped. "As you wish—" As he dragged out the last syllable in a long hiss, he suddenly locked eyes with our guest. "The Orient Express!"

"Venice to Constantinople," said the latter.

Holmes looked at the map and nodded. For my part, I was perplexed. "What are you two talking about?"

"It's quite simple really," he said. "A French and an English army travel on the route taken by the Orient Express. The French army travels from Paris to Switzerland and then on to Venice."

Our guest continued, pointing out the places on the map. "Meanwhile the London army got ahead of him and was already in Serbia, as the blue dot indicates. From there in a year time he reaches Constantinople, the end destination."

I shook my head. "No, that's not what I meant. A few years ago —this was before the Great War— I was invited to a medical congress in Vienna. So I boarded the Orient Express in Paris, from where it passed through Munich on its way to the Austrian capital. Never did it pass through Italy."

"You're talking about the old route, dear Watson," Holmes remarked. "A new line was inaugurated after the War, the Simplon Orient Express, so called because it passes through the Simplon tunnel into Italy and continues South of the Alps to Venice and then on to Trieste and Constantinople."

"It's a very convenient route," continued Sir Tinder. "I frequently make use of it. I love the comfort and the speed."

"Case closed then," I concluded. "You can go to Venice and book your 17:34 ticket."

But to my surprise he started shaking his head. "That will be quite impossible. There's only a single train per day, and it leaves Venice in the early afternoon. By the time mentioned it's already crossing the border into Serbia."

The three of us stared at each other, then back to the map and the note. Finally I broke the silence. "This timing might be a hint. Count the number of centers Turkey owns. There are 17. And 34 is of course the total number of centers, but also the exact double of 17. In other words one player has lined up his units such that in the next round or game year he can conquer the whole board."

"Turkey? But then Paris and London are targets, not starting points."

Sir Tinder's protest didn't yet discourage me. "Perhaps one player controls all the other powers, as in those variants where you start with an empty board, but the centers have been doled out in some random fashion and players get a combination of powers to make it more balanced. This could be an extreme example with just two players involved: Turkey against the rest of the board."

He was still not convinced. "Even if so, surely the 17 Turkish units will easily prevent the other side from conquering all its centers in a single year? Assuming that one can build in every owned center."

"Perhaps he foregoes his builds, taunting the other to take him out and claiming victory if it can't be accomplished. Weird. But as it's a puzzle, let's go with this hypothesis. We know that an army was built in Paris and in London. Paris can only take Belgium, London Edinburgh."

Holmes interrupted me there. "But Edinburgh is also Liverpool's only possible Turkish center."

"Indeed it is. How odd. Is there a mistake in the puzzle? A fleet in London at least could also get to Holland."

"Which is not a city," he remarked. "Nor is Belgium, unless you reduce them to their capitals Brussels and Amsterdam, as some people are prone to do. But what is even more telling is that the riddle speaks of the "first" army Paris, suggesting that more than one was built."

"Good heavens!" I exclaimed. "If there's more than one build, we're talking about two years or more, perhaps even a boundless number. These armies could end up anywhere!"

"No, the number of years is bound to be limited. If I'm not very much mistaken, there are exactly four."

Scarcely taking notice of our surprise, he continued: "But what do you make of that other number in the riddle, the fortnight?"

"It's just setting a date, no?" said Sir Tinder with a hint of anxiety.

"That too. But a fortnight literally means fourteen nights. Subtract from seventeen and you get three, the number of French centers. Which also happens to be his home centers, unlike the other three powers who only own some of their home centers, combined with some other centers."

"I noticed that too," I said. "Germany, England and Austria's centers are distributed a lot more haphazardly. Increasingly so, I'd say."

"Increasingly, yes, haphazardly, not at all," Holmes replied with a grin. "Let's say France starts with her usual 3 units, army Paris, army Marseilles and fleet Brest. She sends them out and captures a few centers. She then builds more units to capture even more centers and repeats this until she has conquered the whole board."

"And what are the other powers doing?"

"There are no other powers. The colors indicate which centers were captured in each consecutive year."

"In other words," said Sir Tinder, "the two German centers of Munich and Venice are the centers captured the first year, the four English centers those for the second year, the eight Austrian centers those in the third year, and the rest, the Turkish centers, are the target for the final year. Brilliant! France doubles her total every year, conquering the whole board in the shortest amount of time."

"Against no opposition," I added. "But then the army in London is actually itself a French army, built after the capture of London. Just like army Paris. Truly a Double French. Impressive."

Holmes, of course, is correct in his interpretation. Well then, can you take it from here and correctly surmise the final destinations of the first army from Paris and the one army built in London?

As we looked closer at the map, I started tracing the first army. "So then, army Paris goes to Munich in the first year. In the second year it moves on to ..."

"Denmark," Sir Tinder said, "the English center that is closest by."

"Right. After that it has a choice of going to Berlin or Norway. And after that it has many more options."

Sir Tinder agreed: "But if we restrict it to cities only, we can whittle it down some: From Berlin it can reach Kiel and Warsaw, from Norway there's St. Petersburg and Moscow. As for army London, we still have the same problem of it competing over Edinburgh with Liverpool."

"It's useless to focus on just one or two units," Holmes said. "Only by reconstructing the whole game can we ascertain ourselves of the correct solution. Let's set up the Diplomacy board."

He fetched his box, laid out the board and placed the three French units on their starting centers. He moved army Paris to Munich and army Marseilles to Venice and picked up fleet Brest. "The position of the armies at the end of the first year is clear, but the fleet can be on any space within a two space radius from Brest that doesn't have a neutral center. But if you look ahead to the English centers, it's the only unit capable of reaching Naples, as army Venice must necessarily continue to Serbia. Therefore it must be in the Western Med."

Seeing us nodding, he continued: "We'll build a fleet in Brest to take London. As such all English targets are accounted for. But we still have one build left."

"A second army in Paris?" I suggested. "To strengthen our presence in the North and fulfill the condition that more than one was built there, as the note implies."

"I would rather suggest a fleet in Marseilles," Sir Tinder said. "It might be hard otherwise to capture all the Turkish home centers down South."

"You both have a point. But looking at the Austrian centers, more specifically the Austrian home centers that get captured in the third year, Vienna and Budapest, our more pressing need is to have a unit in the center. I'll opt for an army in Marseilles."

Double French, After Winter 1901
Click to view the complete history in a separate window
Season: Game Start Spring 1901 Fall 1901 Winter 1901 After Winter 1901

The five units were moved to their English spots: Munich to Denmark, Venice to Serbia, Western Med to Naples, Brest to London and Marseilles to Tyrolia. Four extra units could be built now in five centers, thanks to the freeing up of the German centers captured in the first year. Armies in Munich and Venice were definitely needed, but the two builds in the French home centers again posed challenges.

"I still would build a fleet in Marseilles," Sir Tinder insisted. "First to take Spain and then either Portugal or Tunis."

"And I would still build an army in Paris for the same reasons as before. There are simply too many centers in Russia and the North that are still unaccounted for."

"I agree with the fleet in Marseilles," said Holmes. "But an army in Paris can only move so far. There's no use in sending it to Munich, as we'll be building another army there anyway. And from Ruhr it can only capture adjacent centers in the final year, as both Berlin and Denmark are already conquered by then. There's much more mileage in having a fleet in the North Sea, which can reach both Sweden and St. Petersburg. Let us add another fleet in Brest."

Double French, After Winter 1902
Click to view the complete history in a separate window
Season: Spring 1902 Fall 1902 Winter 1902 After Winter 1902

Nine units were sent on to their Austrian targets: Marseilles to the Spanish south coast, Naples to Greece, Serbia to Bulgaria, Venice to Budapest, Tyrolia to Vienna, Munich to Berlin, Denmark to Norway, London to Liverpool and Brest to the North Sea. Eight more could be built in nine places with the addition of the English centers. We chose fleets for Naples and Denmark, armies for Serbia, Munich and Venice for maximum flexibility, and of course an army for London. As for the two remaining units, "Army Paris," I said with confidence, "Fleet Marseilles?" Sir Tinder asked hesitatingly. With a shrug Holmes approved both of them.

Double French, After Winter 1903
Click to view the complete history in a separate window
Season: Spring 1903 Fall 1903 Winter 1903 After Winter 1903

"Let's start in the South," Holmes said. "Sir Tinder, you were worried about the Turkish homeland. I'll let you do the honor."

Sir Tinder moved Bulgaria to Ankara, Greece to Smyrna and Serbia to Constantinople. "You are right, Holmes, all Turkish home centers can be reached. But let me take this a step further and include the whole Black Sea region. Budapest can move to Sevastopol, Vienna to Rumania, and either Venice or Munich to Trieste."

"Marseilles will give you the answer there."

"Marseilles? Oh right, that fleet can only move to Portugal, which means the fleet in Spain needs to cross to Tunis, forcing Naples to Rome and Venice to Trieste."

"Very well. Now, let's turn North. Dr. Watson?"

Encouraged by how easy this went, I searched for units that only had one possible yellow center to aim for. "I'll start with Paris to Belgium. Norway is the only unit that can get to Moscow, which means North Sea needs to head for St. Petersburg's north coast and Denmark to Sweden. If Munich covers Warsaw, Berlin takes care of Kiel. Liverpool to Edinburgh means London has to capture Holland, but cannot, because it's an army, not a fleet..."

"But if it's an army, it could be convoyed."

"It could, but only if there's a fleet in the North Sea."

"There is one at the start of the year."

"Oh, that one? Sure, it could convoy army London to Holland. And then? Move Holland to Kiel and North Sea to Holland? But that would leave St. Petersburg open and Berlin stranded in Livonia, as it takes three turns for that army to bridge the complete distance."

"But what if you convoy to Norway instead?" Sir Tinder asked.

"And then move that army to St. Petersburg, the fleet to Holland and Berlin to Kiel? That's it! You're a genius, Sul... Sir Tinder."

He ignored the compliment, relieved as he was that a solution was found.

Double French, After Fall 1904
Click to view the complete history in a separate window
Season: Spring 1904 Fall 1904 After Fall 1904

Holmes wrapped it up for us. "So then, gentlemen, if we agree that this is what the map meant to tell, then the question of which train to take is now easily answered. The first army in Paris went up to Norway and on to Moscow, while army London traveled to St. Petersburg. You go meet your lady in the Nikolayevsky Station in Moscow on a train bound for St. Petersburg. Can I suggest you look for her in the dining car? If she's as Russian as her hometown suggests, she might be offering more than just a coffee."

This brought some color on the cheeks of the young man, but he quickly changed the subject. "Now, Mr. Holmes, about that oriental espresso..."

"Coming up!"

— Dr John H. Watson

via Mario Huys (woelpad@gmail.com)