Emmy Award-winning actor Sean Hayes is booked to guest star in a multi-episode arc on the Broadway-themed drama series "Smash," NBC said Monday. The gig will reunite Hayes with his former "Will & Grace" cast member, "Smash" regular Debra Messing. Hayes will play Terrence Falls, a comedic television and film star making his Broadway debut in the musical "Liaisons," based on the novel "Les Liaisons Dangereuses." "Due to a series of comic circumstances, he becomes a major thorn in the side for Ivy Lynn -- [played by Megan Hilty] and other characters," a synopsis said.