The Siren’s Bride by Helen Scott

The Queen is cashing in her favor.
Fae are missing.
Her only hope? A siren and his soul mate.
When Ellie left the fae realm, she knew that its queen, the Morrigan, would one day be calling in the favor that she promised. Did it have to be when she’s in the midst of planning her wedding though? Truth be told, wedding plans and “for richer and for poorer” aren’t Ellie’s favorite things.
Alec knows his relationship with Ellie is fractured, but getting her to talk is a mission he can’t complete. Now, with fae going missing and magic going awry, Alec fears she’s in even more danger. Can he reunite with Ellie before otherworldly forces make “until death do us part” a lot sooner than either of them would like?