Muggles' Guide to Harry Potter/Major Events/Remus' Death

Overview
At the final Battle of Hogwarts, Remus Lupin is killed in battle.

Event Details
When Harry returns to Hogwarts, Neville, who is escorting him from the Hog's Head to the Room of Requirement, assumes that he is there to liberate Hogwarts from the Death Eaters, and uses the charmed Galleons that Hermione had created to recall Dumbledore's Army. Presumably, a member of Dumbledore's Army who either was in the Order of the Phoenix, or whose parents were Order members, passed the word, because members of the Order start to appear through the tunnel from the Hog's Head as well. One of the Order members who we see arrive is Lupin.

After Harry has returned from Ravenclaw Tower, he finds that Ron and Hermione have left the Room of Requirement, saying something about a bathroom. As the whole school has now been summoned to the Great Hall, Harry heads there to see if he can find them. There, he hears Professor McGonagall sending non-combatant students home. Once only students who are of age are left, Order members at head table start assigning specific areas of defence. Lupin will head up the group that is defending the grounds.

Several times during the battle, Harry looks to the grounds to see if he can see Lupin, but is never successful.

After Harry witnesses the death of Snape, Voldemort offers a cease-fire so that Harry can surrender to him and prevent any more loss of life. Harry, returning to the school, looks into the Great Hall and sees Lupin, and his wife Tonks, lying among the dead.

After experiencing Snape's memories, Harry chooses to meet Voldemort, and his fate, in the Forbidden Forest. Finding his way there blocked by Dementors, and being unable to summon a Patronus, Harry uses the Resurrection Stone that Dumbledore had left him, and summons the Shades of Lupin, his godfather Sirius, and his mother and father. He asks if it had hurt to die, and Sirius says that it had not. Lupin adds that "he will want it to be quick", meaning Voldemort.

The shades protect Harry from the Dementors as he walks through the Forest. Reaching the clearing where Voldemort waits, Harry drops the Resurrection Stone, and the shades vanish.

While we are not told this in the book, the author has stated in an interview that Lupin was killed by Antonin Dolohov.

Notable Consequences
Lupin's death once again reminds Harry that his is not the only life that is being affected by Voldemort's reign of power. This reaffirms his decision to do whatever he needs to do to eliminate Voldemort.

Lupin's and Tonks' deaths have left their infant son an orphan. Harry must be deeply affected by this, being an orphan himself, and as godfather having no little responsibility for Lupin's child.

Harry is able to summon Lupin's shade by use of the Resurrection Stone, and learns that Sirius felt little pain from his death; Lupin's silence on the matter seems to reassure Harry that he had also not felt much pain. This somewhat abates Harry's fear at the prospect of dying at Voldemort's hand.

It may be of some note that Lupin is the last of James Potter's friends to die. With his death, Moony, Wormtail, Padfoot and Prongs have all met their end due to Voldemort - in reverse order from their names as displayed on the map.

Analysis
Lupin has been a father figure to Harry, and we can see that Harry is deeply dismayed by his death. The reader is equally dismayed, as it seems that Lupin's death is unnecessary. We are at the very end of the story, the final battle is raging, so many of Harry's friends and heroes have already died... could not Lupin have been spared? We can't, of course, know the answer, but we can speculate. It is necessary to the story that Harry should now voluntarily confront Voldemort and his own death, and he needs support to do that, support which Lupin, alive, could provide. However, at the same time, Harry must face Voldemort alone; the author cannot have Harry's self-sacrifice diluted by the presence of Lupin, a character Harry cares deeply about, and the likely nucleus of a pitched battle as soon as any Death Eater saw him. Were Lupin still alive, it would be difficult for the author to avoid having Harry look to him for the support he needs, and if Harry did seek that support, it would be impossible for the author to prevent Lupin attempting to accompany Harry in to the Forbidden Forest. Dead, but temporarily returned by means of the Resurrection Stone, Lupin, Sirius, James, and Lily can provide the support Harry needs, without either triggering the battle the physical presence of any of them would cause, or requiring that Harry concern himself about their fates as he meets his own doom.

Greater Picture
As godfather to the now-orphaned Teddy Lupin, we can guess that Harry now feels that he has significant responsibility in his upbringing. We never do learn exactly what role Harry plays in Teddy's life, but we believe that it is not insignificant, as in the Epilogue, Harry's children refer to him as "our Teddy." As Teddy had been left in the care of Tonks' mother Andromeda, it is a safe guess that it was Andromeda who did most of the rearing of the young Teddy, with a fair amount of help from Harry and his family.