BOOK 4 of the Gateway Chronicles. Titles must be read in order, and all the books (1-5) are available on NET GALLEY for review:
The Six
The Oracle
The White Thread
The Enchanted
The Scroll
Summary of THE ENCHANTED -
“Enchantments are powerful—the most powerful magic we have,” Rubidius said. “They can change the nature and composition of animate and inanimate things alike, and they can foil the plans of the most determined foes.”

“What do enchantments have to do with me?” Darcy whispered.

“Everything.”

Darcy Pennington’s course was plotted out for her long before she ever stepped foot in Alitheia, but Colin Mackaby seems determined to hamper and confuse the way as much as he can. Darcy begins to suspect that it is not Colin working against her, but a malevolent force working through him—a force seeking to hasten Darcy’s transformation into one of the very creatures she is supposed to fight. Darcy is finally willing to follow the prophesied path, even agreeing to her much-resisted marriage to Tellius, but soon after she returns to Alitheia, everything spirals out of her control. A painful rejection almost pushes her over the edge, and when she demands answers from Rubidius, he provides her only with more painful secrets she must keep from the others. In the meantime, Darcy and her friends finally set out to confront one of Tselloch’s gateways, fulfilling—so they think—the great prophecy of the Six. But when faced with practicing their magic against Tselloch’s evil power, nothing turns out as expected.

Enchantments protect them as sorcery attacks them, and Colin Mackaby dogs their every step along the way. In the minds of the Alitheians, if Darcy cannot repair the breach that has formed between herself and Tellius, nothing will turn out as it was foretold. Darcy wonders, in the end, if there is any hope at all for her, or for Alitheia.