Sean Connery plays an all-knowing patient psychologist / boss who slowly unravels the cause of trouble in a troubled thief. I was not surprised in the bonus feature explanation to discover that Hitchcock had fused 2 characters to attract Connery to the role. It results in an unbelievable superman/businessman. Tippi Hedren plays a part that Princess Monaco was supposed to play. In short Sean is the only good actor in the cast. Not a bad film just ordinary.
Like Spellbound, the MacGuffin in Marnie is a trauma locked away in a character's subconsciousness, exposed by certain dramatic indicators (red, storms) in Marnie's everyday fears. Her anxiety is sublimated by deviant actions like kleptomania and frigidity. So it's a psychological thriller.
Tippi Hedren is married to, and psychoanalysed by, Sean Connery in a rather soapy story of wish fulfilment gone wrong (like Rebecca) of marrying into money and status but which unleashes a nightmare. Hedron does a fine job and Connery could have been a great Hitchcock leading man. Sadly this was his only film for the Master. Diane Baker does good work as Marnie's waspish rival.
The best moment in the film is of Marnie stealing from an office safe with a shoe about to fall out of her pocket to alert a woman cleaning in the next room. It's a pure expression of Hitchcockian suspense. Like a time-bomb, the passage of the shoe out of the pocket being the ticking clock. But Hitch thought the bomb should never go off as that was bad technique. The shoe falls but the cleaner is deaf...
The great clunking calamity in Marnie is the matte painting of a ship in harbour in Baltimore which feels so wrong, especially in 1964. And now it's what I mainly remember Marnie for. The back projection on the hunting scene is also a problem. But Marnie is still a gripping thriller with interesting characters and another beautiful orchestral score from Bernard Herrmann.