The Rithmatist by Brandon Sanderson

In a world where magic is drawn with chalk and used to animate defenses and creatures, a young boy named Joel, who dreams of becoming a Rithmatist despite lacking the magical ability, finds himself embroiled in a mystery at his prestigious academy. As students begin to disappear under suspicious circumstances, Joel teams up with a struggling Rithmatist student, Melody, and their eccentric professor to uncover the truth behind the attacks. Together, they navigate a web of secrets and danger, ultimately confronting a powerful adversary that threatens their world.