Key of Light by Nora Roberts

Malory Price's perfectly planned life has just gone to heck in a handbasket. Her art gallery job, which defined her, is in immediate jeopardy. Then, at an invitation-only reception, Malory and two other women are offered the quest of a lifetime: find the three keys that unlock the souls of three demigods within three months and receive $3 million; fail and lose a year of their lives. They accept the challenge. Malory draws the first quest, and her life turns inside out. Susan Ericksen has a way with accents, from the Welsh and Irish to a Southern drawl; she imbues each of the three women and their corresponding men with very individual personalities, making the story easy to follow, though it has a slow start owing to character introduction.