Hardback, published 1999, 265 pages (the edition I read isn't the one pictured).
The fourth book in the Tomorrow series, Darkness Be My Friend centers around Ellie and her friends. The book starts off in New Zealand, where the protagonists have been for a few months. They're asked to go back to Wirrawee to help with a mission to attack the air field. They're not directly involved with the mission, they're just leading New Zealand soldiers around Wirrawee. Unfortunately, things don't go according to plan.
This series is gradually becoming slower in pace. I know some people don't like it - the first book is action packed, and by this one, there is a lot more retroflection and waiting for things to happen. But I think it's very realistic. These teenagers aren't trained soldiers, they're just teenagers who were in the right (or wrong, depending on how you look at it) place at the time of the invasion. Instead of carrying out missions every few days, they have to rest, think about what they're doing, and try very hard not to be killed.
This book took me a bit longer to read than the last ones, but I'll definitely pick up the next one and eventually finish the series. I'm very involved with the characters, I want to see what happens to them. I wonder if I'm the only one who could see Ellie and Homer eventually getting together. They have pretty strong personalities, and would always be butting heads.
A few things I could learn from this book:
Psychological Effects of War. In The Second Generation, my characters are faced with killing in self-defense, ambiguous enemies, and more. It's not a war setting, but reading this book and The Hunger Games has reminded me that heroes rarely walk away from dangerous, traumatic situations unscathed. Maybe in action movies, but not believable fiction. My female protagonists in The Second Generation and Stones of Cilean go through a lot, and I see Marsden and Collins as great examples.