Katie Holmes and Jonny Lee Miller on Eli Stone
ABC
"She does a song-and-dance number that is the best one we've ever done," costar Matt Letscher tells PEOPLE of Holmes's upcoming guest stint this fall on ABC's fanciful drama, Eli Stone.
"We've done tons of [musical numbers], and she was just phenomenal," Letscher said at the premiere of his new film Towelhead in L.A. on Tuesday.
Holmes, 30, who has been rehearsing in New York City for her upcoming Broadway debut in arthur Miller's All My Sons, also made a good first impression on the set.
"She's the sweetest person in the world, down to earth, simple," says Letscher. "She's just like anybody else. I met her daughter and her husband was on set. It was great."
So, is there hope she'll return for more episodes? "They've left it open," says Letscher. "I think she a had a great time, which made it easier. Everyone was welcoming and it couldn't have worked out better."
