You have quite an interesting piece here with your chosen setting. The imagery is nicely done, but I believe there could be more if you went a bit more in-depth with the emotion. Try adding more description the poem and make it rich with detail. You want the reader's full, undivided attention the whole time and you want it to be captivating. Don't be afraid to really go for it, because in the end it will make this piece all the more thrilling.
Nit-Picks:
In a corner I quivered,
I was aghast.
With fear I shivered,
I thought I wouldn't last.
My eyes were closed tight,
I was filled with fright.
Just then tearing the night,
Came a beam of light.
The rhythm you had going through-out your poem has been really messed up right here. "I was filled with fright." is probably the line that needs changing the most. Your second couplet here needs definite changing, because it sounds weak. You may be able to change that, though, if you make the stanza before it stronger.
Overview:
This poem has a lot of potential to be something magnificent, but you need to be willing to go the extra mile for it. It seems that the thrill that had captured my attention in the beginning of the poem diminished as I read on, so try and work on your last three stanzas. Your last few lines are very important in any piece of work.
Don't get me wrong, though. I thought the true contents of this poem were excellent and you have the right back-bone and structure that will help it become something even better when it's edited. I'll be looking forward to seeing this poem after you have fixed it up a bit and have enlivened it.
