Riddle n°2

Congratulations, you found the used poison! But a question remains: how Serge swallowed the poison?

Fortunately, Cerf’Lock managed to find some clues that could link to the weapon… Will you decipher the coded message?

Here is a piece of advice from Cerf'Lock: in French, a phone can sometimes be named a "tel", for "téléphone".

Found it? Congratulations! Write the answer down, it will soon be useful 😉