We start by examining the flavor and we see reference to an "encyclopedia" and where we're using "missing links". This suggests Wikipedia.
We see in the puzzle that each student is starting with a book, and the puzzle's first section is made up of nine topics. There are the starting points for chains of links to the other titles in the middle section. As the top and middle are alphabetized, but the bottom is not, we can assume ordering is given by the section at the bottom.
Looking at a few Wikipedia pages for these topics, we see that some can go from one to another by links, but we get more than 9 strands/chains because there are missing links. Either manually or by use of Wikipedia's or third party tools, we can find the connections through these missing links. Additionally we note that "Game" in the title is a reference to the several Wikipedia race games that try to find the shortest path from one topic to another (even though we're not racing here, but instead finding paths matching the given titles).
Other things we notice is that we are making chains of length five and that all the starting words at the top are 5 letters. The first letters of our word list share significant overlap with our starting words. This is reinforced by Epoxy and Xalapa, Yucatan.
The first letter of each word in the chain forms the first word in the chain, reinforcing that we're forming chains of length 5. However, we're missing one title per chain, which is always somewhere in the middle, never at an end.
| Start | End | |||
|---|---|---|---|---|
| Anime | Neon Genesis Evangelion | Introjection | Mourning | Ethiopia |
| Canal | Agriculture | Natufian culture | Almond | Levi |
| Epoxy | Polymer | Olmecs | Xalapa | Yucatán |
| Faith | Atheism | Iceland | Tundra | Habitat conservation |
| Omega | Molecular evolution | Escherichia coli | Germany | Art Deco |
| Orbit | Rocket | Bernoulli's principle | Isentropic process | Turbine |
| Radio | Azerbaijan | Decorative arts | Industrial design | Oscar Mayer |
| Robot | Open-source software | Brian Behlendorf | O'Reilly Media | Tarsier |
| Tiber | Iberian language | Béziers | Edinburgh Airport | Royal Mail |
For example, the chain starting with Epoxy is continued with Polymer, (missing link starting with O), then Xalapa, and Yucatán. Even though there may be multiple ways to connect a chain across a missing link, there is only one way using a page that starts with the missing letter from the starting page title. Finally, we organize these missing links according to the order of the clues at the bottom. The missing link matches are:
| Clue | Start | Missing | Chain Position | Index |
|---|---|---|---|---|
| Prehistoric | CANAL | NATUFIAN CULTURE | 3 | T |
| Person | ROBOT | BRIAN BEHLENDORF | 3 | I |
| People | EPOXY | OLMECS | 3 | M |
| Series | ANIME | NEON GENESIS EVANGELION | 2 | E |
| Mediterranean | TIBER | IBERIAN LANGUAGE | 2 | B |
| Biological | OMEGA | MOLECULAR EVOLUTION | 2 | O |
| Profession | RADIO | INDUSTRIAL DESIGN | 4 | U |
| Reversible | ORBIT | ISENTROPIC PROCESS | 4 | N |
| Biome | FAITH | TUNDRA | 4 | D |
The first letters of the starts of the chains read CREATOR OF, and indexing into the missing words using their chain position reads TIMEBOUND. The author of the book Timebound is RYSA WALKER.
This was originally meant for the Hydra round, where we needed hundreds of procedurally generated puzzles but this is still pretty fun as a standalone. We tried to follow a few rules here:
Even allowing the second two bullet points, the chain construction is still unique.