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The Potion Puzzle is the third moment in Harry Potter and the Philosopher's Stone, Chapter 16, Through the Trapdoor.


They stepped over the threshold and immediately a fire sprang up behind them in the doorway. It wasn’t ordinary fire either; it was purple. At the same instant, black flames shot up in the doorway leading onwards. They were trapped…

Zoom levels

This moment has no zooming.

In this chapter, you have to pick the right potions to get to the next chapter. The riddle for this is as follows:

Danger lies before you, while safety lies behind,
Two of us will help you, whichever you would find,
One among us seven will let you move ahead,
Another will transport the drinker back instead,
Two among our number hold only nettle wine,
Three of us are killers, waiting hidden in line.
Choose, unless you wish to stay here for evermore,
To help you in your choice, we give you these clues four:
First, however slyly the poison tries to hide
You will always find some on nettle wine’s left side;
Second, different are those who stand at either end,
But if you would move onwards, neither is your friend;
Third, as you see clearly, all are different size,
Neither dwarf nor giant holds death in their insides;
Fourth, the second left and the second on the right
Are twins once you taste them, though different at first sight.

For those who cannot figure it out



  • Since the giant bottle is not poison and it is a twin to the second from the left, we know these two are nettle wine (2nd and 6th).
  • Therefore, two of the poisons are to the left of these (1st and 5th).
  • The ones at each end are different and since we know the left end is poison, both nettle wines have been found, and it will not help you move onwards, the rightmost bottle sends you back (7th).
  • This leaves 2 bottles and we know the dwarf is not poison, so it must be the one to move ahead (3rd).
  • Finally, the remaining bottle must be the third poison (4th).

So the two you must pick are the small, round, purple potion and the small, blue, squared potion.

And, to complete the moment, you need to take a closer look on the roll right to the potions and pick the two right ones.


Again, the sound in this one is just an eerie, quiet wind.

See Also

Harry Potter and the Philosopher's Stone
Nicolas Flamel
Nicolas Flamel is Finally Revealed
The Hooded Figure
Norbert the Norwegian Ridgeback
Hagrid's Secret
The Egg in the Fire
A Plan for Norbert the Baby Dragon
The Forbidden Forest
Harry Becomes an Outcast
Into the Forbidden Forest
Through the Trapdoor
The Winged Keys
The Chessboard Chamber
The Potion Puzzle
The Man with Two Faces
The Philosopher's Stone
The Hospital Wing
The End-of-Year Feast