Sense Sonnet - Chiller

Shadow Thing

Out of the corner of my eye,
I glimpse a shadowy form dart,
As though in a rush to pass by,
And scurry on to unknown part.
Is my brain just playing a trick,
Knowing that I'm overly tired?
There it is again - gliding quick,
Back at me, as though it is wired
To interrupt its former route,
Because it senses it was seen,
And now must check the seer out.
There's no escaping in between.

Now it's looming in front of me,
With glowing red eyes that can see.