A Trick of Light Lyrics

I wasn't sure if it was a stick, a smudge
I wasn't sure if I was below, above
A trick of light and shadow
Sometimes it's hard to know
Where did you come from?
From oil? From ocean?
Was I not meant to notice?
Then you disappeared
Did I miss you? Did I hit you?
Are you breathing? Am I dreaming?
And then a shock - it moved
A twitch, a groove
Did I give up too soon?
Egret or loon?
An eye reflecting my light

Did I give up too soon?
Heron, egret, or loon?