When Sebastian of Hawkesmere returns from the Crusades he becomes a recluse, locking himself away in an enchanted tower, dabbling in alchemy and magic. When his brother captures a beautiful woman with a satchel full of amazing instruments, Sebastian is enlisted to help discern their purpose and discover where she came from. Rhoswen of Atlantis is unlike anyone Sebastian has ever known, and the answers he seeks will shatter his beliefs and force him to choose between love and duty.

When Trevelan of Atlantis attempts to rescue Rhoswen from the Surface barbarians who have captured her, he finds himself imprisoned as well. When it appears Rhoswen has turned against him, he must rely on the help of an unlikely ally. Miranda of Hawksmere is a healer, and when she nurses the handsome stranger back to health, she can't help but be sensitive to his plight. At great risk to herself, she helps him escape. All Trevelan wants is to return to Atlantis, but Rhoswen has taken his only way of getting home, and he once more has to turn to Miranda for help. Will the magic of his world save her and destroy her?