Another Cold Case: The Enola Holmes Cryptogram

In the feature film “Enola Holmes” (2020), there is a coded text that has no discernible connection to the plot. As far as I know, it is still unsolved.

Deutsche Version

First of all, I would like to mention that Nils Kopal covers two encrypted postcards from my blog on his “CrypTool” YouTube channel. I’m happy about that, of course. The video is absolutely worth watching.


Enola Holmes

Now let’s move on to the feature film “Enola Holmes”, which I blogged about last year. This is a thriller set in Victorian England. The plot revolves around the 16-year-old sister of master detective Sherlock Holmes. When her mother disappears, there is a case to solve in which Enola proves to be even smarter than her famous brother.

The same may be true for the “Enola Holmes” movie as for Nils’ YouTube channel: The makers were inspired by my blog. I’m not entirely sure in the case of the film, but the circumstantial evidence is quite clear. In “Enola Holmes” the following coded newspaper ad is shown (meaning the second one from the top; it consists only of numbers with each word being composed of an even number of digits):

Source: Enola Holmes

I suppose there is a certain similarity to the following newspaper ad from the Morning Chronicle that I blogged about in 2019:

Source: Morning Chronicle

The movie display is shorter than the real thing, and the numbers are all printed in large letters – presumably for the sake of better readability for the movie audience. The encryption methods used are similar: in both cases, a variant of the Polybius cipher was used, with the film version using only the digits from 1 to 5 (which corresponds to the original Polybius cipher):

  1 2 3 4 5
1 A F K P U
2 B G L Q V
3 C H M R W
4 D I N S X
5 E J O T Y

The real ad from the Morning Chronicle, on the other hand, uses the following variant:

  1 2 3
0 A K U
1 B L V
2 C M W
3 D N X
4 E O Y
5 F P Z
6 G Q
7 H R
8 I S
9 J T

I know of no other source that provides comparable information to a comparable newspaper ad. Therefore, I assume that someone on the film’s production team read my blog and was inspired. That makes me proud, of course.


The unsolved cryptogram

There are other encrypted messages that appear in “Enola Holmes.” They all play a role in the plot. However, there is one exception. Already in the first minutes of the film, the following message is briefly shown:

Source: Enola Holmes

As things stand, Enola’s mother left this message. Unless I missed something while watching the movie, however, this cryptogram plays no role in the plot and is not resolved. Here is a transcription of the upper part of the message:


This is an alphabet matrix generated using the keyword IVY LEAF. The J does not appear in it, so that the alphabet fits into a 5×5 matrix. Matrices of this type are used, for example, for the Playfair cipher and the Polybius cipher mentioned earlier.

The lower part of the text on the card reads as follows:


This looks like a Playfair encrypted message. Of course, I already tried to solve this cryptogram with the matrix shown above as a Playfair key. But this did not work.

Or is this a Polybius cipher? For such a cipher you need only 25 pairs of numbers or letters, for example AA, AB, AC, AD, AE, BA, BB, … , EE. However, that doesn’t quite match the letter pairs in the three lines.

After my last year’s blog article about “Elona Holmes”, unfortunately no one could solve the mystery. Will a reader find out more about this cold case cryptogram this time? Is it really a key and encrypted text? Or does the upper part have nothing to do with the lower part? Is the puzzle solvable at all? I will gladly accept hints.

If you want to add a comment, you need to add it to the German version here.

Further reading: Sherlock Holmes and the Pollaky cryptograms


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