THE RIGHT WAY IS THE WAY OF THE OPPOSITE WAY, AND INVERSELY
19.9.13.12.15.19.18.21.15.9.19 will be worth 1
12.15.19.18.21.15.9.19.18.9.13.8.15.4 will be worth 2
9.13.16.16.9.13.9.5.18 will be worth 3
25.1.12.14.18.9.13.16.9.13 will be worth 4
8.15.4.1.12.9.19.18.15.1.6 will be worth 5
18.9.13.13.5.18.18.1.12.18.9.13.12.15.19 will be worth 6
20.18.21.15.15.4.9.18.9.13.8 will be worth 7
9.13.18.9.15.19.19.9 will be worth 8
15.4.1.12.14.18.1.12.10 will be worth 9
19.18.9.13.12.15.19.14.1.12 will be worth 0
Solvability: 
The answer to this clue is certain – but there may be more to it than meets the eye.
Solving this clue reveals 10 French towns that each give a letter and number which will be used to decode the next clue.
B ourges will be worth 1
C herbourg will be worth 2
D ieppe will be worth 3
E pernay will be worth 4
F orbach will be worth 5
G erardmer will be worth 6
H éricourt worth 7
Issoire will be worth 8
J arnac will be worth 9
A ngers will be worth 0
Is there any use for these towns aside from the next clue, or are they more or less random?
How the solution is reached
This is a musical puzzle. The inverted ‘meaning’ of the title involves swapping numbers for letters, then swapping those into musical notes. First you need to replace all the numbers with the letters using the numbers to show the rank in the alphabet, so 1 = A, B = 2, C=3 etc. Then, the order of the letters is reversed, and, whenever a musical note appears in the sequence, we replace the letters composing these notes by the letter corresponding to this note. This solution is suggested by the visual with the list of musical notes, B, A, G etc.
So where the text says ‘LA’ we translate that to A, ‘SI’ we turn to B etc. See this Wikipedia page for the full list.
Here is the detail of the decoding (thanks to WikiChouette) – note the inversion between the 2nd and the 3rd column.
| LA = A; SI = B; DO = C; RE = D; MI = E; FA = F; SOL = G |
|---|
| 19.9.13.12.15.19.18.21.15.9.19 | SIMLOSRUOIS | (SI) OUR (SOL) (MI) S | (B) OUR (G) (E) S |
| 12.15.19.18.21.15.9.19.18.9.13.8.15.4 | LOSRUOISRIMHOD | (DO) H (MI) R (SI) OUR (SOL) | (C) H (E) R (B) OUR (G) |
| 9.13.16.16.9.13.9.5.18 | IMPPIMIER | (RE) I (MI) PP (MI) | (D) I (E) PP (E) |
| 25.1.12.14.18.9.13.16.9.13 | YALNRIMPIM | (MI) P (MI) RN (LA) Y | (E) P (E) RN (A) Y |
| 8.15.4.1.12.9.19.18.15.1.6 | HODALISROAF | (FA) OR (SI) (LA) (DO) H | (F) OR (B) (A) (C) H |
| 18.9.13.13.5.18.18.1.12.18.9.13.12.15.19 | RIMMERRALRIMLOS | (SOL) (MI) R (LA) R (RE) M (MI) R | (G) (E) R (A) R (D) M (E) R |
| 20.18.21.15.15.4.9.18.9.13.8. | TRUOODIRIMH | H (MI) RI (DO) Ourt | H (E) RI (C) Ourt |
| 9.13.18.9.15.19.19.9 | IMRIOSSI | ISSOIR (MI) | ISSOIR (E) |
| 15.4.1.12.14.18.1.12.10 | ODALNRALJ | J (LA) RN (LA) (OD) | J (A) RN (A) (C) |
| 19.18.9.13.12.15.19.14.1.12 | SRIMLOSNAL | (LA) N (SOL) (MI) RS | (A) N (G) (E) RS |
The visual
The visual contains the letters BAGFEDC, which are all musical notes, and there are three musicians, the instruments appear to be a saxophone and a double bass. The double bass has a highlighted shape which suggests a circle and a line of light. It is not clear whether this is significant in any way.
Points to consider
The towns when plotted on a map appear to be in a particular order, creating a clockwise rotation of a circle around Bourge. This may be significant because Bourges is the city we discover in the ‘Opening’ clue 530.
Cherbourg and Bourge are mentioned in clues x and 530, the other towns do not appear in any other clues.
Max did use the plotting of towns on a map in a previous treasure hunt in the Treasury of Malbrouck one clue involved connecting 40 cities on the map to draw a ram’s head. This shape does not appear to be anything recognisable.
Many towns could have been chosen to represent the letters A to J but it seems Max deliberately chose towns that form a rotation of clockwise direction from Bourge. If the title’s ‘opposite way’ is to be believed we might be expected to think counter-clockwise.
In conclusion
We have discovered an A=0, B=1, C=2 method to decode the next clue.
It is not clear whether the towns themselves, or their order or placing on the map, gives information that serves some other purpose in solving the Golden Owl treasure hunt.
There is no obvious use for Angers = 0. Why did Max include this town and number?
It is possible that the 10 towns and cities listed here are a red herring, or perhaps they are used at the ‘super solution’ stage.
See also