At the Spring School, toghether with normal participants, there were some secret agents, members of the Lada Borová Revival Clan. For several days, they remained unnoticed. But then, a warning appeared on the board in the lecture room. It also mentioned a code breaking game. Who are these agents, you might have asked. What is the Lada Borová Revival Clan, who is Lada Borová? And what about the game, would you have to solve some ciphers? But nobody seemed to know anything more.
On Friday, during the talk given by Vítek, a seemingly innocent lemma was proved. But the corollary of the lemma was surprising: it stated that the game had just begun. You had to go through the proof of the lemma again and seek a secret message. The solution was to take the first letters of the seven parts of the proof: BUS STOP.
This also made many people stop to believe the statement of the lemma. But the proof is really correct! :)
Inside the bus stop, there was an advert of th Jarník & Prim company creating notebooks. If you searched your notebook, you found a graph with weighted edges. The task was to find the minimum spanning tree of the graph using the Jarník/Prim algorithm; and, of course, find out what the edge weights are by solving several puzzles. Having foung the minimum spanning tree, you had to use the weights of the selected edges as indexes into the 'happier liFe with minimum cost!' catchword. That gave you the message 'learn french'.
During lunch on Saturday a meeting with one of the secret agents was announced. The agent gave you some important instructions about the game and lists of vocables in German, French and Slovak. And those who had already solved the previous task knew that they should concentrate on French. Really; if you translated the words "GRIMPE AMES LOTO VIRAGE" using the first letters of the listed words, you got "BRIDGE OVER MALA VLTAVA".
This was where the outdoor part of the game begun. You found a list of talks mixed together with meal names. After sorting the listed events according to the time when they happened the first letters gave "road southeast 15 min ladder".
At the second post, you were given several options how to proceed, with a hint telling you to ask the fence. Nearby, there was a tall fence made of wooden poles. On some of these poles you could find small pieces of paper, each with a single letter on it. If you arranged the letters according to the height of the poles they were attached to, they spelled the hint "THE LAST", telling you to follow the last option of the menu.
In the haybarn, there was a list of many strange questions, like "We like Rakvicky. Do you like them too?" or "What is the Czech word for kohlrabi?" Each line contained one question mark. The hint below stated that as soon as you read the whole question, you already have the answer. Indeed, the answer was to take one letter from each line -- the one just before the question mark. Solution: "BOARD 6 NATURETRAIL".
The sixth board of the naturetrail showed you the first page of a paper called "Improved Bounds for the Post-finding Problem". By reading the abstract, you found out that the post is situated on the top of a hill and that, with constant probability, the fourth post does not mention the name of any hill or other geographic feature.
The solution was hidden the in bibliography: each reference coded one number (or the decimal point), together it gave "1068.3" which was the height of the Vyhlidka hill.
On the top of Vyhlidka you found a Mattoni bottle containing a message. According to the message, you had to find a secret agent and tell him a passphrase. A hint was provided on the first board of the naturetrail, saying that you should carefully read the contents of the mineral water that you drink. The contents of this Mattoni bottle contained the passphrase "Mattoni uz neni".
The secret agent gave you three pages that had been obviously torn out from a notebook. The first page contained the Morse code, the second page was "intentionally left blank", whereas the third one was "accidentally left blank". The message "MAP OF CR" was coded (by Morse code) in the shreds on the top of the pages.
Behind the map near the hotel entrance, there was the touching story of Lada Borova, a noble lady who tortured people by forcing them to solve her ciphers. She was detested, murdered and became the ghost appearing at midnight in the nearby forrests.
A secret agent led you to the forest to meet Lada Borova and break her curse. You managed to break the curse sucessfully by saying the words "Byla to pekna hra, dekuji" to Lada. As a reward, you won some ice cream. The ice cream was then carried to the hotel, eaten, and there was much rejoicing.
The secret agents :-)