After an young girl is bought from slavery, she is taken to a school where she becomes a witch, where she uses her abilities to kill her former master and save her family.

Great, so we know the ending. Who needs to read the book now? Change to "where she must learn to use her powers" and you've got yourself a functional logline

When a young girl is bought from slavery by a warlock, she learns the art of witchcraft and returns to kill her former master and find her missing family.

Tada.... there is the Logline. I understand the movie now. It's ?Taken? with magic

Richiev, I've always loved your reviews and consider them the utmost of constructive criticism taken to heart. I agree with everyone about the fact that this is a plot, not a logline. I've been rewriting it for some time and I think this is what I was really looking for, but still need to hone it a little more.

When a young girl is bought from slavery by a warlock, she learns the art of witchcraft and returns to kill her former master and find her missing family.

The inciting incident that leads to the cause and effect. I almost have it. I don't know what possessed me to write a silly plot when this is a logline community.