Multiplying by zero

The curtain unfolds
I take a look
An army of numbers
It saw, it took

Pi broke the gate
And e led the horde
But we had zero
And zero was bored

They marched on
Towards their end
“Zero is a number
He is our friend”

Alas, they faded
No more pi or e
A blank null field
Stared at me

Impossible to solve
The problem was over
Multiplying by zero
Had closed that door