Immediately after you put Longing into play, check to see if it is part of your longest chain of adjacent Emotions, or in a chain tied for longest. If so, give Longing a +2 Intensity token. Longing wants to be part of something big.
This is a Strong Emotion. It enters play, when the Mild Emotion DESIRE is Empowered.
Empower is a Spirit Action available in the Full Game rules.