Affiliation: Order of the Phoenix
Our favorite werewolf goes through a lot in this book – not only is he deeply involved in the fight against Voldemort's regime, he's also a new husband preparing to be a new father. And not just any father – he's worried, naturally, about what will happen to the baby. Will it be a werewolf, like him? Will it despise him for what he is? Remus is full of a lot of pressing and unanswerable questions, and we don't envy his emotional torment.
Of course, we don't see that much of this, since he doesn't get to hang out with Harry, Ron, and Hermione all that much, even though he offers to. It's this offer that drives Harry up the wall – he can see that Remus is feeling uncertain and insecure about the prospect of fatherhood, and the idea that any parent might desert his child (when he didn't have to) is too much for the orphaned Harry to cope with. The resulting fight is what kicks Remus back into shape. After some deep thinking, he returns to the pregnant Tonks, ready to take on fatherhood. And, in appreciation for Harry's sound advice, the new parents ask him to be godfather.
Sadly, after ecstatically witnessing the birth of their son Teddy, Remus and Tonks don't get to enjoy parenthood for too long, and both die in the Battle of Hogwarts. However, the experience of fatherhood seems to have changed Remus deeply and made him a happier man somehow – the ghostly Lupin who returns with the Resurrection Stone to guide Harry to his death, along with his other loved ones, knows that he died to give his son a better world and a happier life.
We admit it – we were really torn up when Lupin died. Why, oh why did he have to die? (And so darn close to the end?) After Book 7 was released, a lot of other fans felt exactly the same way, and here's how Rowling justified her decision:
I wanted there to be an echo of what happened to Harry just to show the absolute evil of what Voldemort's doing. The fact that you leave orphans and you leave children who then have to make their way in the world uncared for and unprotected. And – so that's why I killed the two [Lupin and Tonks] that, you know, you know about in this book. Which I hated, hated doing because I love them both as characters. (source)
OK, so that does seem to make sense. Lupin, a new father, dies fighting Voldemort, just as Harry's father (and mother) died years ago in the first war against the Dark Lord. Thank goodness Teddy Lupin, unlike Harry, has a godfather around to help watch over him (and no Voldemort lurking in the shadows). Unlike Harry in his early years, Teddy will not go "uncared for and unprotected."