This is an experiment of nested puzzles.
The answer of each puzzle is necessary to solve the next one. Sometimes you have to manipulate it, sometimes you have to open your eyes (and mind).

Run, to Westminster Abbey!
Nevermind, to Gatwick, ok!
Please, don't waste time,
I want to keep my dime!
The original one is black,
never goes off track!

enter image description here

What's the answer?

Notes: I will add hints every 24 hours.
Sadly I couldn't add more than 5 tags, these are those I would include as well: , , .
I accept partial answers, I will personally upvote those who solve at least 1 unsolved puzzle or submit a wrong, yet plausible solution
Teamwork is appreciated!

Useful link: http://www.mobilefish.com/

Hint #1

Don't consider the picture until you solve the riddle.

Hint #2

Actually the picture is the 3rd puzzle to be solved.

Hint #3

The 2nd puzzle is hidden in the 1st answer!

Hint #4

It may be difficult to solve puzzle #4 without solving #5. It's impossible to solve #5 before #4.

Hint #5

Puzzle #5 requires a "different point of view"

Hint #6

+ = Final Answer

Hint #7

The final answer is an English word.

Hint #8

There is only one reference to Chemistry.

Hint #9

Looking for a different point of view? Turn upside down your head!

Hint #10

What do you usually need to solve a puzzle?

Hint #11

Look around like a bat!

Hint #12

You've to deal with a basic kind of cipher. Once you know the key and the encrypted message (and you know both, I assure), you should be able to decrypt the message with few attempts!

Bounty awarded to Len, the one who solved the highest number of puzzles.

Answers Credits:

Puzzle #1: Len
Puzzle #2: finsternis
Puzzle #3: finsternis
Puzzle #4: Len (rand al'thor contributed too)
Puzzle #5: Len + rand al'thor

  • 1
    $\begingroup$ Given the link you mention, would the [computer-puzzle] tag also be appropriate? $\endgroup$ Commented Apr 5, 2015 at 23:12
  • 1
    $\begingroup$ I highly suspect that information is hidden in the image via mobilefish.com/services/steganography/steganography.php ,and I also suspect the answer to the riddle is the key to decrypt the information. However, I'm silly and can't solve the riddle, however I suspect it's a famous train (The original one is black, never goes off track) $\endgroup$
    – Tryth
    Commented Apr 6, 2015 at 1:35
  • $\begingroup$ I just had a neat idea, have 5 riddle poems which include the word KEY, which should be replaced by the answer to the previous riddle. The 1st poem's KEY being the answer to the last poem, and have people love this cycle. $\endgroup$
    – warspyking
    Commented Apr 6, 2015 at 2:59
  • 1
    $\begingroup$ I suspect that this is just the first puzzle, and the next one is found in the hidden message in the image. Meanwhile, for what is written here, the word "express" sticks out to me, although it's not the password on the mobilefish site's steganography service. $\endgroup$
    – Glen O
    Commented Apr 6, 2015 at 7:07
  • 1
    $\begingroup$ Great puzzle, great teamwork so far as well. +1 The site needs more of theses things (not only cryptograms though). $\endgroup$
    – BmyGuest
    Commented Apr 13, 2015 at 5:41

6 Answers 6


Edit 4 - The final answer for Puzzles 4 and 5 (revised based on hints)

Puzzle 4 and 5 - Using the solution for Puzzle 3 (as found by finsternis) as well as efforts by rand al'thor:

79 periodic number - suggests using Gold from the periodic table or the Golden ratio of 1.6180339 or its inverse of 0.6180339

1459238 If you can't see the answer, you should use it! - the hints suggest that this is the ciphertext and the Golden ratio could be the key.

Therefore treating this as decoding suggests using mod-10 and subtracting
6 1 8 0 3 3 9 from 1 4 5 9 2 3 8 results in 5 3 7 9 9 0 9 which is the answer for Puzzle 4.

Then looking at this upside down provides the answer to Puzzle 5 which is G O G G L E S

Puzzle 1 Using Tryth's suggestion of a train, I think the riddle describes a:

London taxi which has traditionally been black. Other names could be hackney carriage, hackney, hack, black cab, cab, black taxi, taxi, or remise.

I assume the Mobilefish password for the picture is an anagram of one of the names. However, these anagrams do not work:

  • $\begingroup$ Excellent, first puzzle solved. The answer is indeed one of those you listed, but which? Take a closer look and try to find out which one contains a puzzle! $\endgroup$
    – leoll2
    Commented Apr 7, 2015 at 8:13
  • $\begingroup$ Again a good try! Well, if anagrams aren't the key, let's try something else... $\endgroup$
    – leoll2
    Commented Apr 7, 2015 at 20:15
  • $\begingroup$ It may be that the time and dime of the riddle refers to a maximum speed of said cab, or the fastest model, etc? (Haven't found the right key on mobilefish yet though) $\endgroup$
    – Aify
    Commented Apr 7, 2015 at 21:17
  • $\begingroup$ @Aify the cab is only involved in puzzle #1 $\endgroup$
    – leoll2
    Commented Apr 9, 2015 at 13:23
  • $\begingroup$ @Len I really love how you got adieu Bach, it's incredibly surprising to see how many hidden unintentional additional puzzles a problem can have! Sadly, this isn't the real answer to my puzzle! $\endgroup$
    – leoll2
    Commented Apr 12, 2015 at 8:52

[Feel free to edit and remove spoiler tag if that is preferable for cooperating.]

Continuing where Len left off, the relevant answer to the first puzzle is



these are also hexadecimal digits. 0xcab hex = 3243 decimal, which is the password to the image.

Decoding the image gives

Good job, but it's not over!
Things will get harder now!

79 periodic number


If you can't see the answer, you should use it!

My thoughts on this:

The seven digit number is part of the expansion of pi with missing digits:
pi = 3.14159265358979323846264...
message = 14 592 3 8
missing = 3 1 65 5 9
I've shown the missing digits up to where 79 appears in pi. I think the last part of the message is saying to use these missing digits. Also FWIW 79 is the number for gold in the periodic table.

  • $\begingroup$ Gallium, Terbium, and Praseodymium... Tb and Pr were both discovered by someone named Carl Gustaf Mosander.... $\endgroup$
    – Caleb
    Commented Apr 8, 2015 at 5:02
  • $\begingroup$ That line "If you can't see the answer, you should use it!" seems suspicious. I'd expect something like "Use this number!" or even nothing at all. The wording seems like it might be a hint, but maybe not. $\endgroup$
    – Caleb
    Commented Apr 8, 2015 at 5:23
  • 1
    $\begingroup$ Writing the missing digits 316559 in ASCII gives USA; $\endgroup$
    – Aravind
    Commented Apr 8, 2015 at 8:42
  • $\begingroup$ I confirm that you solved puzzle #3 (the picture). There's one valid observation in your thoughts about #4. $\endgroup$
    – leoll2
    Commented Apr 8, 2015 at 11:56
  • $\begingroup$ @Aravind: How? I can't see how you encoded that number into ASCII. $\endgroup$
    – user88
    Commented Apr 11, 2015 at 20:30

First, a summary of progress made by others on Puzzles 1-3; then everything on Puzzles 4-5 is my own work.

Puzzle #1

The rhyming riddle given in the OP was solved by Len; solution #1 is a

London taxi or cab.

Puzzle #2

Solution #1 was interpreted by finsternis as a

number written in hexadecimal. $CAB_{hex}=3243_{dec}$,

so solution #2 is


Puzzle #3

Solution #2 was used by finsternis as the password to decode the picture in the OP using the given link. Solution #3 is:

Good job, but it's not over!
Things will get harder now!

79 periodic number


If you can't see the answer, you should use it!

Puzzle #4

My interpretation of Solution #3 is as follows.

"79 periodic number" - 79 appears on the periodic table as the number for gold, and the only "golden number" I can think of is $\phi=\frac{\sqrt{5}+1}{2}$, the golden ratio.

The hints have told us that we're now looking at a cipher puzzle, so we need to find some way to put together $\phi$ (as a key perhaps) and the string of numbers 1459238.

I believe Solution #4 is

5355?7?, where the second ? is either 6 or 9 and the first is probably either 0 or 4. For my reasoning for this, see below.

Puzzle #5

The hints tell us that we need

lateral thinking at this stage. More specifically, we need a "different point of view", involving "turn upside down your head".

We also have the clue

"If you can't see the answer, you should use it!"

which so far we haven't used. This clue makes me think of

GLASSES, which looks like the number 5355?7? when turned upside down. (An upside-down 6 looks like a lower-case g, and an upside-down 9 like a capital G, so I'm not sure which is the final digit. An A looks a bit like a 4, and an upside-down a looks a bit like a 0, so I'm not sure of the third-to-last either.

This was my reasoning for Solution #4. It fits Hint #4 - indeed everything seems to fit together. I'm sure I've got the right answer; I just need to do a little more work on Puzzle #4.

The final solution is ...


  • $\begingroup$ Thanks for the summary! Until now, you're the one who made the biggest progress with puzzle #4. Keep thinking! PS: The puzzle is fully english, no foreign words. $\endgroup$
    – leoll2
    Commented Apr 8, 2015 at 12:00
  • $\begingroup$ phi + bilious = fabulous? ;) $\endgroup$ Commented Apr 8, 2015 at 19:27
  • $\begingroup$ i'm thinking not being able to see the answer implies it's a colorless gas. (oxygen?) $\endgroup$
    – abcd
    Commented Apr 8, 2015 at 22:29
  • 2
    $\begingroup$ Also, if you turn your head upside down, 1459238 becomes BEZGSHI on a calculator. But I don't think that has to do with anything... $\endgroup$
    – user88
    Commented Apr 11, 2015 at 20:25
  • 1
    $\begingroup$ @randal'thor Impressive, you pretty much solved the 5th puzzle partially skipping the 4th. I can't say the answer "Glasses" is correct, but you're very very very very close! $\endgroup$
    – leoll2
    Commented Apr 12, 2015 at 13:35

Alright, haha, I think I went way too far in the wrong direction, but I'll post this just in case it's miraculously on the right track. I searched the hex code of the image for the missing digits of pi 316559, and there was one match. I then replaced those 3 bytes with all of the named hex colors for gold. One of them, EEC900, made an interesting pattern in the lower-right hand corner of the image, part of which looks weirdly similar to a Piet program. That's where I stopped because probably this is totally wrong, but who knows.


  • $\begingroup$ Wow, I really like the results you got doing that! Sadly, you aren't on the right track, but I still appreciate the attempt! $\endgroup$
    – leoll2
    Commented Apr 8, 2015 at 11:53

based on the answer from rand al'thor:

I think the answer for #4 could be

billionaire based on "billious" and "air" (the answer which can't be seen)

  • $\begingroup$ Good attempt, but you're still far from the solution! $\endgroup$
    – leoll2
    Commented Apr 10, 2015 at 15:37

Puzzle 5: Here's some thinking about puzzle #5. Maybe it helps to get further...

if you turn the number upside down imaging that it would be a 7 segment based view you get: 8E265hl or 8E265hI if this would be hex, you get: 582245 I or l - no idea how to get further

  • 1
    $\begingroup$ I really didn't understand your strategy, can you explain better please? $\endgroup$
    – leoll2
    Commented Apr 10, 2015 at 15:36

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