Wednesday Weeks and the Tower of Shadows: Book #1 by Denis Knight and Cristy Burne
In a world of magic, can science save the day? Wednesday Weeks never wanted to be a sorcerer’s apprentice. She’d rather study science than magic. But when her cloak-wearing, staff-wielding grandpa is captured by a power-hungry goblin king, Wednesday must find a way to embrace her magical heritage and rescue him from the dreaded Tower of Shadows.
Luckily, she’s not alone. Her best friend Alfie is a prime-number fan and robotics expert who’s all-in on Wednesday’s epic plan involving parallel universes, swords of power, and a wise-cracking talking skull. But it’s going to take more than science, magic, and the world’s cutest robot to take down this bad guy. Because the goblin king is playing for the ultimate prize – and Wednesday and Alfie just walked into his trap…