If I am wel informed, the project called Le ThermoZéro is a project for a Tintin book and not for a Jo, Zette and Jocko adventure.
No, Chevet, it is both, but you are not the first person I have had trouble convincing of this! Thanks for the link to the Greg page, it is very interesting: it is particularly so because it points out that while Hergé could not work with the script, he did in fact think that it was good. What it misses is what he did with it next.
As I explained in the conference article quoted above, once Hergé had given up Greg’s script for a Tintin book, he passed it to Bob de Moor to transform Greg’s same basic scenario into a JZ&J story.
This actually isn’t news, as in their biography
of Bob de Moor (Bob de Moor: 40 ans de bandes dessinées, 35 ans aux côtés d'Hergé
, Lombard, 1986), Bernard Tordeur and Pierre-Yves Bourdil published some of Bob’s notes and sketches of the JZ&J work. What was
news was that the book which Bob developed was substantially complete, and the possibility was that it could be published.
Hope this clarifies things for you - I can really recommend the de Moor biography, if you want a look behind the scenes at his work with Hergé and on his own.