SOLVED. YA Portal Fantasy about a two schoolchildren who get lost in a yellow fog while on a field trip and end up in a medieval fantasy world. [s]

[Jade]

1) The book begins with the two kids going on a field trip when the bus ends up stopping near an empty field. The kids get out but one boy and one girl see a yellow fog creeping towards them that is so thick they can't see through it. Both of the children end up getting lost in it and when they escape they are in a medieval fantasy world.

They end up in a castle (I really want to say it was Camelot) and the girl develops magical powers while the boy just learns to fight with a weapon. I'm pretty sure I remember them either referring to the girl as Merlin or reading that he was her teacher???

There was an attack on the castle and they helped defend it. After the attack they both ended up in the fog again and when they got out they were back in their original world.

The girl had been thriving in the other world and had never really fit into the first one so she was really upset about it. I'm not sure if she tried to find the fog again or not.

I don't really remember the boy's storyline because he annoyed me and I didn't want to rad about him.

Edit: I just remembered that when I wanted to read it I would look for books with all green covers and get excited if I saw any with a large tree on the front. I don't know if that was the actual cover tho.....

2) I think I read it somewhere between 2000 and 2005.

[Becca]

Warriors of Alavna by N.M. Browne?

[Jade]

Becca wrote: "Warriors of Alavna by N.M. Browne?"
OMG I THINK THAT'S IT!!!!! Thank you!!!!