Snape in the graveyard

[weirdsister06]

No: HPFGUIDX 92755

Sue wrote: 

What it Snape followed Harry to the Graveyard wearing an 
invisibility cloak.  His mark burned, he knew where they all were 
and he had to assume that the missing Harry and Cedric were there as 
well.  Snape then could have fixed the cup to take Harry back to 
school (if he survived) and later born witness to DD about the truth 
of everything Harry saw and heard, perhaps even adding the names of 
the DE's Harry did not know.
> 

There are questions about Snape and the graveyard, to be sure.  He 
must have had an excellent cover story for Voldemort since he didn't 
show up when the mark first burned.  In relation to Sue's theory, I 
have two additional questions: does Voldemort share DD's 
ability to see through invisibility cloaks, and does Snape share 
DD's ability to become invisible without a cloak?

weirdsister06