Interestingly, the earlier versions of the book (1937 and 1943) included as the first frame a newspaper cutting saying that Tintin was indeed on holiday
That clipping would have made the whole thing so much easier, and it was probably just a throw away idea in the original! Funny that the book which cried out for it (the revised for English language version) lost it!
Let me add a few comments
Hi, Chevet! I was meaning in terms of the UK continuity, those things are in England, not Belgium. The translators relocated the stories, as well as the language.
Therefore in the British books, they are written as if Tintin and Co. don't
live in Brussels.
When addresses are translated into English, Labrador Road, where Tintin lives, is said to be in London.
Also, Marlinspike does exist when Black Island
is published, because they bought it at the end of Red Rackham
, which was already out (in Britain, that is. It may happen differently in the continuity of L'Îsle Noire
The Thom(p)sons going back to England
shows us Tintin is taking a continental holiday, away from the UK; it might
mean he was in fact in Wales, Scotland or Eire, but the notice on the train says otherwise.
There is no reason to assume that he isn't
in Germany, as that is where the train says it is coming from, and there is no indication where he gets on.
He could - on the evidence - be on holiday in either Germany or Belgium. From what's shown in the book, there is no way to tell.
I was playing the game of identifying what facts can be derived from the text and illustrations, seeing how they fit against the way the translators have presented the story, and finding a way to explain the situation.