The Hogwarts refreshment witch

[potioncat]

No: HPFGUIDX 104829

 
>       Gina now: Notice we have never seen the driver? Lupin said 
he must go
> have a word with the driver but we never know why or what was said 
or who he
> is. Does anyone other than me find this funny?
> Gina


Potioncat:
Either the driver has the capability to contact Hogwarts and that is 
what Lupin was doing.  Or Lupin used that as an excuse to leave the  
Trio and go somewhere else on the train to contact Hogwarts.
(We're told by McGonagall that Lupin sent word ahead.)