SOMETIMES, it's the little moments you remember the great actors for.

Robert de Niro has a scene in Goodfellas where he makes it clear that the troublesome Morrie has to go. It's all done with the eyes: sideways glances, an unblinking stare, eyebrows arched, meaning and menace shot through every frame of this unbroken shot.

It's there in the self-disgust with which Brando tells Rod Steiger, "I could have been a contender" in On the Waterfront. It's there in Gene Hackman's triumph as he drives away at the end of Heist, having outwitted his girlfriend and her new man before they even know it.

It's there, too, in Sir Alec Guinness's performance as Smiley in the BBC TV version of Tinker, Tailor, Soldier, Spy. Gary Oldman does a creditable job in the recent film but for me it's overshadowed by Guinness's masterly portrayal, which was broadcast in 1979, near the end of a brilliantly distinguished career. There's one particular early scene where Smiley, retired prematurely by the Circus, has been brought to a house in order to lead the interrogation of Ricki Tarr, an agent who has gone missing and has now returned. Up until now Smiley has seemed affable, if slightly distracted and lost. Tarr (played by Hywel Bennett) is chatty, sure of himself. Just before the interrogation, Smiley, polishing his spectacles, asks Tarr for his exact current status. "No-one at the Circus knows you're in England?" he affirms. "You're officially absent without leave." He bows his head to put his glasses back on, and when he raises his head again, the eyes are like chips of ice and his voice becomes glacial, metallic: "On the wanted list." The temperature in the room has suddenly dropped by several degrees. It lasts just a few seconds but to me it's electrifying.