Falling Through Time by Nancy Scanlon

From the day the Fates decided he would be the warrior to train and lead a group of time-traveling clansmen, Reilly O’Malley has been certain of everything. He’s gone into every battle, verbal or physical, knowing that he will be victorious. Rescuer of many, protector of the O’Rourke clan, knight in shining armor―he lives up to all the titles with the full confidence of a man who knows he will live forever.

Gwendolyn Allen has been in love with Reilly, her best friend, since she met him more than a decade ago. But dreams of a happily-ever-after are dashed when Gwen finally accepts that Reilly won’t return her love for him. She’s determined to move on, and she has…almost. When she learns that all Protectors are destined for one woman only, she can only assume that Reilly’s repeated rejection of her means that he’s already found his soul mate.

Reilly is tired of dancing to the Fates’ tune, and when he and Gwen find themselves together for three weeks prior to a wedding, the Fates decide to step in. They give Reilly a taste of what his life would be like without their protection, and suddenly everything Reilly knows is shaken to its core. When his otherworldly abilities begin to fall through time, Reilly may have to trust in something other than fate.

He might just have to trust in love.