The Blackwood Witches

Valaria Blackwood lives a peaceful life alone in the forest, practicing her unique brand of wild magic away from a wizard society that shunned her years before. But when a wizard assassin breaks into her home one night, her quiet life begins to crumble. He tasks her with using her magic, derived from a strange affinity with spiders, to aid him in an evil plot. If she refuses, she knows he will kill her.

Kestral Blackwood, Valaria's sister, enjoys a comfortable position as an apprentice in the elite wizard society. But when her fellow wizards begin to fall ill from a mysterious and fatal sickness, and she learns her ostracized sister might have a hand in it, she must face the past she's worked so hard to leave behind and try to save not only Valaria, but their entire world.