PBS begins tonight a four-part series of contemporary Indian films, scheduled for the improbable hour of 10, and any fan of this exotic genre will want to plan the evening around the first offering, "The Golden Fortress."

It will be a long evening, for like most Indian films, this one, while only 2 1/2 hours, seems longer. "The Golden Fortress" is a 1974 Satyajit Ray film, in color with English subtitles. It is an adventure-mystery, rather more commercial than his usual subject matter, and quite engrossing -- particularly if you revel in the atmosphere of the Subcontinent.

The story has to do with a 6-year-old boy whose parents are worried about his remembrance of a previous life. It's not the reincarnation they are worried about -- this is India, after all -- but the fact that the memories are keeping him awake at night drawing pictures of scenes from his former life. They take him to a parapsychologist, who offers to take him to the scene of his former life.

Meanwhile, two bandits who have read newspaper accounts of the boy conspire to kidnap him for the jewels they think are hidden in his former home. The plot gets thicker and thicker with the addition of a private investigator/bodyguard, his young assistant and a traveling novelist.

There are overtones of American detective movies in the character of the investigator, who smokes cigarettes while staring meaningfully into the cosmos, but where else but India would the bad guys try to commit a murder by letting a scorpion loose in the intended victim's bedroom? None of the violence actually takes place; the pistols sound like cap guns, and hats are shot off rather than heads.

India is famed not only for the size of its film industry, which is the largest in the world, but for the style of its movie actors, which is also among the largest in the world. They specialize in a kind of performance that would be considered burlesque here, but is totally acceptable in the florid, wonderfully melodramatic context of most Indian movies. Ray was one of the first directors to go for a more naturalistic style, which at times was so low-key as to be boring. The performances in this movie, however, are somewhere between those two extremes, although the traveling novelist and the two bandits are clearly veterans of the grandiose style.

The other films in the series are "The Whole Sky," a first film by Basu Chatterji about an arranged marriage; "The Forest," a 1973 film by playwright/actor Girish Karnad set in a village; and "27 Down," by the late Awtar Krishna Kaul, a love story.