This is a YA book series read in the mid 2000s. One of the last books had a dark cover of a lightning storm over plains.

I believe this story is about 2 siblings, guy and a girl, who start learning magic from a powerful being, hundreds of years old, in a cave.

The goal is to fight an evil, I believe the mentor's sister. They are both very powerful (cosmic power?) beings. She may be called Morgana, not sure.

The main girl eventually falls in love and marries the mentor, and she gains some of his power and a despondent view towards humanity/time (think Dr. Manhattan).

Final battle involves lots of evil monsters, not sure if the good side had an army.

  • Hi, welcome to SF&F! You might take a look at the suggestions for writing a good question; there might be more details you can add.
    – DavidW
    Commented Jan 2, 2019 at 2:50
  • My first thought was The secrets of immortal Nicholas Flamel (siblings, magic, a character called Morrigan, some of the mentors are quite old) but too many details are missing (cover, girl married mentor, Dr Manhattan powers), hence this'll stay a comment
    – Jenayah
    Commented Jan 2, 2019 at 4:41

1 Answer 1


The Guardians of Time trilogy by Marianne Curley.

Isabel and Ethan are childhood friends. Their mentor is Arkarion who is 600 years old. And they are tasked to fight the Order of Chaos led by Lathenia, another immortal.

It contains the following books:

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.