Passion.

As a weed beneath the ocean,
As a pool beneath a tree
Answers with each breath or motion
An imperious mastery;
So my spirit swift with passion
Finds in every look a sign,
Catching in some wondrous fashion
Every mood that governs thine.
In a moment it will borrow,
Flashing in a gusty train,
Laughter and desire and sorrow
Anger and delight and pain.