The 5th Wave, Book 1

The 5th Wave is set in the aftermath of an alien invasion and paints a fairly realistic picture of how human civilization might be disrupted by bird-borne viruses, electromagnetic pulses, and an artificially induced tsunami.

The primary characters in The 5th Wave all find themselves in extreme situations, where they are forced to do things they might never have contemplated in their lives before the alien invasion. Each, however, struggles to do what's right for those they care about, even if it means personal sacrifice. Cassie is determined to be reunited with her little brother. Ben wants salvation after abandoning his sister. Evan wants to protect Cassie at all costs. How they deal with these motivations in the face of harsh reality is what gives the book its thematic heft.

Under constant physical threat, the characters in The 5th Wave have very little time to think about romance or sex. Cassie has a crush on high school football hero Ben Parish, but she's most strongly attracted to mysterious Evan Walker. When she's unconscious, he bathes and changes her from her bloody dirty clothes into a nightgown, something she realizes when she regains consciousness. While she recuperates at his cabin, she can't help staring at his hair, smile, and rear end. There's a lot of kissing and thinking about sex in the parts of the story involving Cassie and Evan: She contemplates whether he had sex with his ex-girlfriend, makes out with him on a bed, and wonders what it would be like to have his hands all over her body. They share an experience of total intimacy, though not intercourse.