Good story Severus. As far as grammar and spelling you did very well, but I expected that. You did have a couple of errors, but two of them were uses of whom instead of who and both were your character talking. Now if he's the kind of guy who always uses whom even when it's not appropriate that's fine. The other error is in this sentence:

Willem, for his part, could scarcely done this encounter justice in his imagination if he tried.
You should have put the word have in that sentence.

The next assignment is another short story but using all the tools you have to try to make sure it is error free.

P.S. Do you have any idea how difficult it is to use a spell checker when the author uses words like vith and vat? lol