Filmed on dazzling locations in England, the Agatha Christie dramatization ''Murder Is Easy'' (CBS, Saturday, Jan. 2, 9-11 p.m.) is an utterly predictably unpredictable delight.
Although it stars Bill Bixby and Lesley-Anne Down, Olivia de Havilland steals the show in a totally unexpected character role. Helen Hayes pops up in a cameo as well.
Early in the film, somebody says ''So long as nobody suspects you, murder is easy'' and the race is off. The flow of suspects will daze you, the flow of clues will puzzle you, the switches and double-switches will delight you.
Although Agatha Christie might be a little dismayed at some of the modern computer plot twists, she would indoubtedly adore the delicious English countryside, the congregation of marvelous English eccentrics.
At some point, viewers may tire a little of the twists and turns of the plot, at the shallowness of a few of the main characters, but nobody will tire so much that they would consider turning the dial.