The 39 Clues Wiki
The 39 Clues Wiki

The Janus Serum is the serum of the Janus Branch. Drinking this serum increases the user's Janus mental capacity and creativity to a superhuman extent. Those powers are related to artistic thinking, from composing a concert to a burglary. It is composed of the Janus Clues:


The Janus Serum, which was found by Amy and Dan in The Emperor's Code on top of Mount Everest.


  • This serum contains the second most ingredients with 8. The Madrigal Clues also consist of 8 Clues, while the Lucian and Ekat are 7 and Tomas having 9 Clues in their serum. It also contains liquid silk, which is the hardest Clue to obtain.
  • The Janus Serum was found on top of Mount Everest and was unusually placed there by a Tomas teacher, adventurer, and mountain climber named George Mallory. It was made by Emperor Puyi while he was still in the Forbidden City.
  • Nobody has ever drank the serum, expect maybe Jane Cahill.

Plot Overview[]

The Emperor's Code[]

During this time, the serum was actually at the top of Mt. Everest. Most of the competitors for the 39 clues were there, fighting over the vial. Amy finally got the vial, but when she saw Ian Kabra about to fall off the edge of the mountain, she chose to save Ian instead of the Serum. The Serum fell down and was destroyed.

Vespers Rising[]

Gideon Cahill gave the Janus serum to his second youngest daughter, Jane.

Janus Logo