There is one like this for the other books too in this series, so why not this one. I've just finished reading the book, and i'm happy to say that almost nothing has been left out, only things have been added, things that are good, luckily. There are some things left out, but once again, no major changes to the actual story, even though they are a bit sad.
For those who don't know, Day of the Dragon is the original of this book, written in 1989 if I'm not mistaken. For a discussion about the original Power of Five series, please go here:
http://anthonyhorowitz.com/msgboard/index.php/topic,1702.0.htmlNecropolis starts with a whole explanation of how they managed to survive the attack in Peru, and how they got to know who Scarlett is. This is actually a good thing, because in the original, people kind of simply knew that Will was the fourth (Will being the original character for Scarlett) The whole business with the doors was new anyways, but it's cool to see how scarlet's discovering a door leads to the discovery of herself. Also her home situation, how she ends up going to hong kong, things like that is a bit more explained in this version. One thing I miss though is the white Lotus Van trying to get her in London, and especially the man with the crocodile leather shoes. He was a good character, and turns out to be important for the rest of the story in Day of the Dragon.
Another thing that is more fleshed out is the way Matt and Richard go to Hong Kong. Jamie comes with them, which isn't so in the original. What i do like however is that the false names they use to travel are the names they had in the original book, I like that little touch

Scott's character is also a bit more fleshed out in this version, if only the fact that Matt doesn't really trust him completely yet.
But then as soon as Scarlett's on her way to Hong Kong, things are pretty much the same in general, except for some minor details.
Firstly what has been left out:
There is no one trying to contact her at the airport (like the girl trying to contact Will), Mrs Cheng in Day of the Dragon is constantly knitting (and uses her knitting needles to kill the guy trying to contact Will/Scarlett on the boat when they go on their cruise, a portion that i liked a lot and that has now been taken away). the shape shifters are a lot less described. Mrs Cheng does not die by being strangled by her own scarf in the typhoon at the end. Karl doesn't go in his original form. Mrs. Cheng isn't the master of the shapeshifters
Things that have been changed:
The way of getting the message to Scarlett is different than Will. The fortune telling is also different, here they use a bird, whereas in Day of the Dragon, Will had to pick a scroll out of a closet with a lot of prophecies. I've already mentioned Mrs. Cheng's death.
The Master of the Mountain...well now there's a change. The original idea is sort of the same, with the White Lotus and that changing into the Triads...but in the original, the Master of the Mountain was a part of the group that still believed in the White Lotus' original ways. In fact, he is ancient and he himself was one of the original members. Also he himself is an elderly man that likes to take care of the roses in his garden, and that can control the weather himself. He is Will's father....and put him in the orphanage himself.
The way that Scar manages to get away at the Peak is also completely different. In the original there is a whole fight/flight with the tram and all of that. Also he doesn't go up there with 'Mrs. Cheng' but he manages to escape from her in a busy market. Since there is no man with squeaky shoes, there is obviously also a change in the whole of that scenario. In the original it is while he's staying with Lohan (the man with the squeaky shoes actually, just a different description) and his niece (the girl trying to contact him at the airport), that he discovers that he can actually control the weather rather than predict it. So in Day of the Dragon, you know it a lot sooner. There he also stays on the boats in Kowloon, rather than go straight to the fireworks factory. The way of trying to get Scar out of Hong Kong, and her being captured by her father is pretty much the same though.
If I remember correctly, in the original it wasn't the captain that betrayed them, but the one crew member on his boat. Too bad actually, i liked the captain.
Things that were added:
The jade pendant wasn't there in the original, so that's new.
All of them coming together at the end in the temple
Scarlet being shot (now there's a huge change)
And them being scattered all over the world. In the original it just ends with Martin, Will and Richard escaping in a helicopter, and then being on their way to Peru, to be with the others. Here the ending is completely different. but that's mainly ebcause in the original there isn't the whole business with the doors.
Over all, I'm actually quite impressed with the changes made. Since in the original this was my favourite, I was very weary of the rewrite, I was afraid that like with Nightrise, almost everything would have been rewritten. Raven's Gate and Evil Star were more or less the same as the originals, just with more added detail and some minor things left out, but nightrise was very different, so i was afraid it would be the same with Necropolis. But in fact, this is probably out of the four the one that stayed closer to the original.
The villains in this version are a little bit less "evil". Hmm, that's not the right word. In the original the villains seem to come straight out of a horror movie. Here they are a bit more realistic. Over the years, that has become a trend with Anthony's writing though, a trend that I am surely not supporting. In his older works his villains were grotesque, misshapen, horrible,...and that was part of it's appeal. In his newer works, the villains are much more human. They're still a little bit grotesque, but not so much as they were. While it makes the books probably more acceptable for a wider audience, it does seem to take an element of humour out of them...
Over all, I'm quite happy with this version, my fears were ungrounded. I can't wait for the final and last book, let's hope that this time round he will actually finish the series.