Albus Dumbledore: Address.
Newt Scamander: What’s that?
Albus Dumbledore: A safe house in Paris.
Newt Scamander: Why would I need a safe house in Paris?
Albus Dumbledore: Should things, at some point, go terribly wrong, it’s good to have a place to go. You know, for a cup of tea.
From the movie Fantastic Beasts: The Crimes of Grindelwald (2018)
Whose address does Dumbledore give to Newt in Crimes of Grindelwald, in case he needed a safe house in Paris?
Nicolas Flannel. Dumbledore’s long time friend Nicolas Flannel has let him use his house as a safehouse for any potential allies. Dumbledore then gives a card with the address to Newt. Newt comes to the safehouse with Jacob, Tina and Yusuf, when they’re tracking down Credence.
