What makes you sense a heartbeat?

Is it the fear of the cold air,
The echo of the silence, the shattered light,
The existence of nothing but the ghosts of your thoughts;
Because you can see the hums that once existed
Tumble out and melt away,
Leaving you, alone, lying next to your fears.

Or is it the anger, betrayal, despair
That fuels your heart,
Makes it burn against your lungs 
And pumps the blood that you so need,
Until it sizzles and cracks and leaves its ashes
Leaving a trace of the broken glass, the midnight lightning.

But it all leads back to love
The summer breeze, the starlight, the hum of love
Hands lingering, fluttering at his touch
The brilliant pain of breathless looks
Goosebumps forming on your skin, hair rising,
And your veiny heart, pumping love, 
Beating fast until it pounds against your ribs
And echoes your heartbeat through space.