"Mrs Peel," says the whimsical John Steed, "we're needed," and The Avengers are off on another improbable adventure. Diana Rigg, the British star who plays Emma Peel on the ABC-TV series, has a lot in common with the character she portrays. Off the set, she wears the same sort of mod styles - pants suits and mini-skirts. An ex-model, Diana finds they set off her height (5'8 1/2") and willowy figure to advantage. Her past, too, is quite exotic. She was born in Doncaster, England, but spent her childhood in India, where her dad was with the Indian Government Service. Back in England, she studied at the famous Royal Academy of Dramatic Art. A series of theatrical success led to TV, and The Avengers. Diana, who's unmarried, lives in London's elegant Mayfair district. Future plans for this auburn-haired, brown-eyed beauty include lots of movies. Her main interest at the moment is becoming a superstar. With her looks and talent, she's bound to be!