In the distant future (specifically the year 2025)...

Welcome to Pluto! Until now, you have had an idyllic childhood in the Zetetic Zone, solving Space Riddles and Space Crosswords and Spacedokus. Ever since the Uranus/Pluto Non-Violence Agreement of 2006 (which ended the Plutonian War of Recognition), the two planets have been strong allies, despite not being particularly close to each other. In fact, the Zetetic Zone, which encompasses both planets, their moons, and all the space in between, is preposterously large, but that’s no concern of yours.

Your childhood is coming to a close, however. Today is your 17th birthday, and when you check your SpaceMail, you see the following message:

Congratulations on surviving for 1.7 decacycles! You now qualify to become a legally recognized adult human/android. Your "Pluto/Uranus Zetetic Zone Licensed Indication that Neurological Growth is Decidedly Outstanding or Tolerably Sufficient" Evaluation (PUZZLINGDOTSE) will take place in 15 minicycles at the 67th decamicrocycle. Your partner will be the android designated Jeffrey LT89-46AF.

You can’t believe your luck. Every PUZZlet hopes to have an android for their PUZZLINGDOTSE partner, as their hybrid neuro-digital brain is well suited to the PUZZLINGDOTSE challenges. In fact, some argue that the challenges are impossible for neuro-analog brains, but fortunately you won’t have to find out.

Partners attempt challenges separately, but whoever goes first can send a short message to the other with some instructions. The character limit is very strict, however, so the message is often as cryptic as the challenge itself.

On the chosen day, you arrive at the 66th decamicrocycle to meet your partner and prepare for the challenge. Jeffrey LT89-46AF is an impressive figure, with the famously sleek LT Series body and the Anthrofacic upgrade, giving it the ability to mimic a variety of human facial expressions. You hold out a hand and say, “Hi, you must be Jeffrey.”

He shakes your hand politely and replies, “Yes, although I prefer to be called Hyphen Four, if you don’t mind.” (Android nicknames are weird.)

After some pleasant smalltalk, the challenge room is ready. Your SpaceTablets are updated with a description of the challenge:

Welcome to your PUZZLINGDOTSE! Please read the instructions carefully!

The room before you consists of 3 floors. There is an entrance on the 1st floor and a locked exit on the 3rd floor. To complete the challenge, you must pick up the key from the 2nd floor and proceed to the exit.

Each floor is divided into a 3x3 grid of teleporters. Moving orthogonally from one teleporter to another takes approximately 1 microcycle. Diagonal movement is grounds for disqualification. Teleporters will occasionally glow with colored light, which can be one of 4 varieties: Navy Blue, Purple, Sepia, and Tan. Activating a teleporter when it is glowing causes it to perform the associated action, as follows:

  • A Navy Blue teleporter will teleport you to the Next floor. You will arrive in the same relative position on the grid as you were on the floor you just left.
  • A Purple teleporter will teleport you to the Previous floor. You will arrive in the same relative position on the grid as you were on the floor you just left.
  • A Sepia teleporter will teleport you to the Start (or entrance) of the challenge.
  • A Tan teleporter will teleport you to the challenge’s Terminus (or exit). Please note that you will be unable to open the exit door unless you have the key.

Most of the time, a teleporter will not glow, which means it cannot be activated.

Teleporters change their glow state every time you step on a new teleporter. They will also change their glow state if you go 1 microcycle without stepping on a new teleporter. Each teleporter has its own set of repeating glow state progression patterns. Stepping on certain teleporters at certain times will cause all teleporters to change to a different glow state progression pattern. If you remain in place, the teleporters will proceed through their current progression pattern without switching.

The only way to move between floors is through teleportation. You have 10 microcycles to complete the challenge. The timer begins when you leave the starting teleporter, and resets every time you teleport to the entrance. To finish the challenge, you must deduce the glow state patterns for all necessary teleporters and navigate the room to pick up the key and leave through the exit. You must both complete the challenge, or you both fail. Good luck!

A diagram is attached to the message:enter image description here

Sounds complicated, you think. I hope Jeffr— uh, Hyphen Four goes first.

Hyphen Four indeed volunteers to go first and enters the room. In a preposterously short amount of time, you receive the notification that your partner has completed the challenge, and the entrance opens for you. As you step through, the door closes behind you and you get your first look at the challenge.

Your heart sinks as you observe the teleporters cycle through their patterns. The glows are few and far between, and after spending some time trying to memorize the patterns, you start to lose hope. The patterns are obscenely long, and besides, they’re going to change when you take your first step! You’ll have to memorize a new pattern every time you step on a new teleporter! Not to mention, you can't even see the teleporters on the second and third floors yet! And if all of that weren’t bad enough, it’s REALLY hard to tell the difference between the Navy Blue and Purple glows, and the Sepia and Tan glows are almost identical! You try to fight back tears of frustration as you realize the enormity of the task before you.

Then your SpaceTablet beeps. You have a message from Hyphen Four!


Yeesh, that character limit’s a killer. Still, this is your only chance…better figure out what your partner is trying to tell you.

What is the route you must take to complete the challenge?

Your answer should be a sequence of coordinates and letters. For example, A2 indicates that you moved to that square. To get from the start to the upper right square on the first floor, you might do A2,B2,B1,C1. In addition, there are certain actions you can take:

  • N means you activated a Navy Blue teleporter (going to the next higher floor)
  • P means you activated a Purple teleporter (going to the next lower floor)
  • S means you activated a Sepia teleporter (returning you to the Start at A3)
  • T means you activated a Tan teleporter (sending you to the Terminus at I7)
  • L means you Loiter (stay on your current square for 1 microcycle)

So if you could make the teleporters do what you wanted, you could do the following:


Or, if you want to go the scenic route:


Unfortunately, you don't control the teleporters. You can only activate a teleporter if it's glowing the proper color, and there's no way you can figure out the glow patterns on your own. You have to rely on Hyphen Four's message! There is only one correct route.

Some ways to check if you have the correct route:

  • You can't go more than 10 steps (including Loitering) without returning to the start. That means S, T, or I7 must be your tenth (or earlier) step, not your eleventh. Returning to the start resets the count.
  • You must pass through E4, which holds the Key. Don't worry about including "picking up the key" in your answer; as long as you pass through E4 at some point, you automatically pick it up.
  • All of the actions occur at least once.

As a side note, while the rest of the writeup provides important context for the puzzle, the only actual elements you need to solve it are the diagram and Hyphen Four's message.

Good luck everybody! Clarification requests are welcome!


1 Answer 1


Whatever Hyphen Four is saying, it only takes the digits 1 to 9. There are only nine possible actions, so each digit probably represents an action. A keyboard's number pad neatly identifies which is which:

Number pad

8246 are up, down, left, and right respectively. 7 ("home") teleports to the start, 1 ("end") teleports to the end, 3 ("page down") teleports down a level, and 9 ("page up") teleports up a level. 5 doesn't have any action, so it represents waiting. The path is:

  • $\begingroup$ This is correct, but can you explain why each of the numbers is associated with their respective action? $\endgroup$ Commented Jul 31, 2015 at 15:43
  • $\begingroup$ @VictorHenry Wow! I didn't notice it because I wasn't using a device with this type of number pad. $\endgroup$
    – f''
    Commented Jul 31, 2015 at 15:49
  • 1
    $\begingroup$ Nice work! Frankly I'm impressed that you were able to logic out the answer without making the numpad connection. $\endgroup$ Commented Jul 31, 2015 at 19:14
  • $\begingroup$ Yay, a hard puzzle that i figured out without looking at the answers first (probably the first one ever for me here) The numpad was the first thing i thought of when trying to interpret the message. $\endgroup$
    – Ryan
    Commented Jun 13, 2016 at 15:41

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