Lately they've forsaken the theater for the silver screen, but even British stage royalty like Dames Maggie Smith and Judi Dench need to return to their roots. This month they will perform together for the first time in Breath of Life, a new David Hare play (Theatre Royal Haymarket; www.ticketmaster.co.uk; October 15-December 25). Hollywood is close on their heels. Making their U.K. debuts are Woody Harrelson and Kyle MacLachlan in On an Average Day, a new comedy by John Kolvenbach (Comedy Theatre; www.ticketmaster.co.uk; through October 27), and Glenn Close as the tragic Blanche DuBois in A Streetcar Named Desire (Lyttelton Theatre; www.ticketmaster.co.uk; starting October 8). With such an invasion of stars from the States, it's a good thing that theaters are being spruced up all over London. Renovations to the venerable Almeida and Hampstead theaters should be complete by year's end.