If someone is crying out for something they really want it or need it.
Example: The outer suburbs are crying out for more public transport.
Something that is in the head exists only in the imagination. It's an idea rather than the reality.
Example: His sickness is all in the head.
To lay to waste or lay waste to is to destroy.
Example: The retreating army laid waste to the countryside.
heading toward a dispute
Example: The competing interests of the people concerned about this patch of forest and what should be donme with it are on a collision course.
pay attention to what I'm saying
Example: She'll accept our offer, you mark my words.