Tommy and Annie being each other's source of hope in Those That Wake.
Laura's letter to her parents at the end of Those That Wake.
What We Become has Laura and Mal's conversation before the climax, and Mal's admittance that Laura was his only source of hope for anything in the world, and even happiness was a foreign emotion to him except when near her.
Mal's sacrifice to save Laura at the climax of What We Become.
Laura bringing hope to every place she goes at the end of What We Become.