Lovely new chapter! I admire the way you think of ways to circumvent problems that occur because of the changes compared to canon; having Dumbledore show him those memories instead of him getting to the diary via Ginny was brilliant! And so very IC too!

Just one minor thing, 'serpensorum' should be 'serpentorum' and is the genetive plural of 'serpens', so the translation should be something like 'beware of the road of serpents, strangers' (otherwise the genetive singular form is 'serpentis') and 'cave' is a singular imperative form and 'hospes' is also singular,so I don't see why the translation shouldn't be 'beware, stranger'. If you wish for the strangers to remain plural, that would be 'cavite, hospites'. Sorry to bother you with such a minor issue...;)