What is the theme in The Key to Midnight by Dean Koontz?

Romance is another theme in the book. Joanna Rand does not like to let men get close to her. Whenever Joanna feels something stronger than lust for a man, she has panic attacks. Joanna freezes these men out, sending them away without explanation, afraid, for reasons she does not understand, to allow these men to get close to her. When Alex Hunter comes into her life, Joanna panics sooner than ever before, unable to be near him just hours into their relationship. Joanna tries to freeze Alex out, but he will not let her. Alex knows things about Joanna, and he cannot let her push him away.