The Red Scrolls Of Magic by Cassandra Clare

A warlock and his Shadowhunter boyfriend set out on a whirlwind trip through Europe that quickly turns into a hunt for a dangerous ancient magical text that could unleash havoc if read. Along the way they face old enemies, tangled loyalties, and personal ghosts from their pasts, testing both their skills and the strength of their relationship. The story blends humor, romance, and fast-paced urban-fantasy action as they race to stop a threat that reaches into both of their worlds.

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