Miles returned to the screen as the trampy wife of schoolteacher Robert Mitchum in David Lean's "Ryan's Daughter" (1970, written by Bolt), cuckolding him to make savage (and beautifully photographed) love to Christopher Jones in empty buildings and open fields, reestablishing her sexual voraciousness en route to a Best Actress Oscar nomination. "Lady Caroline Lamb" (1972, her husband's disappointing directing debut), identical in structure to "Ryan's Daughter", placed her in a seemingly unworkable marriage (this time to Peter Finch), and she scandalized everyone by conducting an open affair with Lord Byron (Richard Chamberlain) and another with the Duke of Wellington (Olivier), finally reaching a kind of accommodation with a forgiving husband. In Alan Bridges' "The Hireling" (1973, adapted from the L.P. Hartley novel), a film that explored similar master-servant dynamics as had Losey's "Servant", she fell into the arms of her chauffeur (Robert Shaw) before recovering her well-bred sense to reject love with someone beneath her class as impossible. She was also the soft center of the explicit sex scenes in "The Sailor Who Fell From Grace with the Sea" (1976) and traded on her sexy image as late as Michael Radford's "White Mischief" (1987).
Miles delivered a highly effective change-of-pace portrayal as the harried mother-of-three in the blitz-torn London of John Boorman's semi-autobiographical "Hope and Glory" (1987). Along with Losey's earlier "Steaming" (1984), it signaled her move from melodrama and exotica towards "realism" and domestica. In keeping with her more mature screen persona, she played titled women (Lady Ashley and Lady Sybil) for the ABC miniseries "Harem" (1986) and "Queenie" (1987), respectively, and was the aging courtesan-turned-respectable Countess de Secret in the TNT movie "A Ghost in Monte Carlo" (1990). "Dandelion Dead" (1994), aired as part of PBS' "Masterpiece Theatre", marked her last screen appearance to date, but she has kept busy. Encouraged to write by her paramour Olivier, she has penned three memoirs since 1993 and a novel published in 1998, as well as hitting the boards for her one-woman songfest, "The Widow Smiles". The sister of director Christopher Miles, she acted in his short "The Six-Sided Triangle" (1963), portrayed a film star in his "Priest of Love" (1980), a literate account of the last years of D.H. Lawrence (Ian McKellen), and was part of the cast for his proposed "The Plumed Serpent", canceled just before shooting was to begin in 1974.