“What’s behind the door?” Gun Roswell

Blue door

Step in through the door
In the colour of blue, that is
If you dare, did I

Give you a scare or
Is your face so pale by nature?
So do let yourself inside

Who knows what scary things
You may find, after all, this is
A tale for the odd

And peculiar people, who like
To dabble in the adventures beyond an
Explanation from this world maybe

Even horror or some sort
Of supernatural thing, which will make your
Heart sing, until it it

Pops out and lays still
On the ground until you pop it
Back, and all is well.

Again?