Task: Question Answering
Input (English): Passage: Russ Ward is a Broadway producer with a 30-year record of success who has been out of town. On returning to New York, everybody wants a piece of him: ex-wife Kathryn Ward, hard-drinking playwright Jeremiah "Mac" MacDonald, magazine reporter Roy Morton, business manager Miles Atwood, and lawyer Charles Montgomery, one after another.
The main topic of discussion is Give Me Your Hand, the new play Russ is producing. The reporter hears it's in trouble, but Russ says that's untrue. It will be ready for its Boston tryout right on schedule, he vows.
Kathryn keeps reminding him of his age, which Russ likes to lie about. Russ tells loyal young secretary and student actress Ellie Brown it is likely time to retire because the new show is a mess. He and writer Mac have a story about a middle-aged man romancing a 22-year-old woman, and just can't seem to make it work.
Ellie is in love with Russ, so much so she proposes marriage to him. That gives him an idea. What if the play had the young woman pursuing the man? That way he wouldn't seem such a lecher. A delighted Mac rewrites it, and everyone involved works on it at the Long Island mansion where the former actress Kathryn lives, partly thanks to her alimony from Russ.
A rich backer named Bacos wants in, but Atwood says his money isn't needed because an anonymous angel is financing the whole show. Ellie reads the woman's part, and strikes everybody as perfect for it. Gordon Reynolds, an up-and-coming young actor in Ellie's acting class, gets the male lead, and promptly falls for Ellie, but she's being led on by Russ, who doesn't discourage her love for him. 
Question: At whose house does Jeremiah "Mac" MacDonald do the rewrite?
Output (English): Kathryn Ward.