Only Connect’s ‘impossible’ Missing Vowels puzzle looks like gibberish — until the pattern clicks
At first glance, these four strings look like complete nonsense:
BGB GBGB GBG
PTTN GPTT NGPT TNGPT TNGP TTNG
MSS SMS SSM SS SMS SSM SSS
LS TL ST LST LS TL ST
But hidden inside them are 20 perfectly ordinary words — and the key to solving the puzzle is a deceptively simple pattern involving the five vowels.
The Only Connect challenge asked for “Five words in alphabetical order”, leaving contestants to work out what the apparently random combinations of consonants could possibly mean.
Once the rule is spotted, the entire puzzle falls into place.

A notoriously difficult quiz format
Hosted by Victoria Coren Mitchell, Only Connect is known for questions that require contestants to find connections between clues that can initially appear completely unrelated.
The show tests a mixture of general knowledge, language, logic and pattern recognition. Its four rounds include connection questions, sequences, the notoriously difficult Connecting Wall and the quickfire Missing Vowels round.
In the Missing Vowels round, vowels are removed from words or phrases and spaces can be altered, leaving contestants to reconstruct the original answers.
That was the format behind this particularly intimidating puzzle.
The challenge appeared in Series 12, Episode 37, featuring the Verbivores and Cosmopolitans, with the category “Five words in alphabetical order.”
That category was the first major clue.
The first sequence reveals the trick
The opening string was:
BGB GBGB GBG
It looks almost impossible to decipher until the missing vowels are restored.
The five words are:
BAG
BEG
BIG
BOG
BUG
The consonants remain essentially the same, while the middle vowel changes in order:
A → E → I → O → U
And because those words appear alphabetically, the category suddenly makes sense.
That same principle is repeated throughout the puzzle.
The second set follows the same pattern

The next sequence was considerably longer:
PTTN GPTT NGPT TNGPT TNGP TTNG
Restoring the vowels produces:
PATTING
PETTING
PITTING
POTTING
PUTTING
Again, the five words differ through their vowels while maintaining the same underlying consonant structure.
And once again, they are arranged alphabetically according to the sequence:
A, E, I, O, U.
What initially looks like a collection of random letters is actually a carefully stripped-down set of familiar words.
The third group confirms the pattern

The third line reads:
MSS SMS SSM SS SMS SSM SSS
Its hidden answers are:
MASSES
MESSES
MISSES
MOSSES
MUSSES
By this point, the pattern becomes much easier to recognise.
Each group contains five words, and the missing vowels move through the same alphabetical sequence.
Once contestants identify that mechanism, the final set becomes much more approachable.
The last five words
The final sequence was:
LS TL ST LST LS TL ST
The answers are:
LAST
LEST
LIST
LOST
LUST
Once again, the vowel changes from A to E, then I, O and U, while the basic consonant structure stays intact.
So the four apparently meaningless lines actually conceal four groups of five words:
BAG — BEG — BIG — BOG — BUG
PATTING — PETTING — PITTING — POTTING — PUTTING
MASSES — MESSES — MISSES — MOSSES — MUSSES
LAST — LEST — LIST — LOST — LUST
Why the puzzle looks so difficult
The clever part of the question is how much information disappears when the vowels are removed.
Take the final group:
LAST, LEST, LIST, LOST, LUST
With the vowels stripped away, the words are reduced to essentially the same consonant pattern:
LST
The altered spacing makes the strings look even more mysterious, encouraging contestants to search for meaning in places where there isn’t any.
The real task is much simpler: restore the missing vowels and notice that they progress through A-E-I-O-U.
The category is the crucial clue

The phrase “Five words in alphabetical order” gives contestants two important pieces of information.
There are five answers in each group, and they are arranged alphabetically.
That immediately makes the five vowels a potential key.
The first sequence provides the breakthrough especially clearly:
B_G
can become:
BAG, BEG, BIG, BOG, BUG.
Those five words naturally follow alphabetical order, revealing the mechanism that unlocks the remaining groups.
From gibberish to obvious
That is what makes this kind of Only Connect puzzle so effective.
Before the pattern is recognised, BGB GBGB GBG looks like little more than meaningless code.
After the answer is revealed, BAG, BEG, BIG, BOG, BUG seems almost embarrassingly obvious.
The same is true of the other three sequences. Nothing obscure needs to be memorised. The challenge is simply recognising what information has been removed and using the category to work out what belongs in its place.
It is a perfect example of the gap between an Only Connect puzzle being seemingly impossible at first glance and suddenly making complete sense once the hidden rule finally clicks.