Running Hot
Running Hot by Jayne Ann Krentz
From the jacket:
Ex-cop Luther Malone, lifelong member of the secretive paranormal organization known as the Arcane Society, is waiting to meet Grace Renquist. Hired as an aura-reading consultant in the quest for a murder suspect, she's got zero field experience. She's from tiny Eclipse Bay, Oregon. She's a librarian, for heaven's sake.
As for Grace, she's not expecting much, either, from Malone, who walks with a cane and isn't so good with a gun. Nice résumé for a bodyguard.
But even before they reach their hotel in Maui - where they'll be posing as honeymooners - Grace and Luther feel the electric charge between them. Problem is, they need to remain vigilant day and night, because it soon becomes clear there's more going on here. Rogue sensitives - operatives for the underground group Nightshade - are pouring into the luxury resort as if there's a convention.
While the pair's employers at Jones & Jones scramble to get them...