The 39 Clues Wiki
The 39 Clues Wiki

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Iodine is one of the 39 Clues that make up Gideon Cahill's master serum. This is the only combo that can only be made by Cards in different Card Packs.


Janus writer Mary Shelley wrote the novel Frankenstein and hid the Clue in the novel. The book was put in the Janus Hollywood stronghold but no one was creative or clever enough to solve the puzzle.

Crystalline Iodine


Iodine can be unlocked by completing the Frankenstein's Secret Card Combo:

About Iodine

Iodine is a chemical. It is used for antiseptics. It can also purify water for drinking. It is also used in salt sometimes.

Iodine Symbol


The scene first shows the book. It opents to a page to show the title and the picture. Then, on the next page, a drop of ink makes the text dissappear, leaving a few letters that spelled 'IODINE' with the crest.