Chemical Reaction

Not the recipient for affection
I am the catalyst

The bug that enters the system
And sends out all the countermeasures

The spark that sets the world spinning

The lure for the animal in the den
To be exposed to the elements

The intruder flushing out the landlord

Until there is a vaccine or a replacement

I am evil for upsetting the balance
I am good for initiating the change

When the process is done

I am not the recipient for affection

I am just the catalyst