[HPforGrownups] Re: Chapter Discussion: Prisoner of Azkaban Ch 20: The Dementor's kiss

[Liz Clark]

No: HPFGUIDX 190800

> Potioncat now:
<snip>
Snape came because he saw Lupin on the map, and wouldn't have known Harry 
was involved until he found the Invisibility Cloak at the Whomping Willow. 
He wouldn't have known about Ron and Hermione until he reached the doorway.

Taya:
I got distracted by something Potioncat said, sorry!
How did Snape know the Invisibility Cloak belonged to Harry? He does clearly 
know this by time he gets to the shack, but before then, when did he suspect 
or realise Harry had one?