Beautiful tale of the power of innocence; The House of Prague Street, by Hana Demetz. New York: St. Martin's Press.$8.95

At the end of this novel a teen-age girl walks up the steps to her grandparents' old home in a small town in Czechoslovakia. Her family, all Jewish except for her German father, have perished during World War II. This is the house where she spent many happy summers.

A man dressed in black opens the door. He motions for her to come in. Others, all in black, emerge from the doorways. They stare at her. Then one speaks:

"Go away child, and don't come back. Don't disturb us. You don't know, you haven't seen. You haven't suffered. You haven't endured. We are the last. Don't disturb us."

The passage is one of the most tragic in a book of deep tragedy and heartwarming beauty. And yet the tragedy is not just in the pain of these Jewish survivors of Nazi concentration camps. In their intense sorrow, they don't recognize the gift of innoncence this girl could bring them -- the gift of forgiveness and understanding that would lift the pain. If only they were willing to be disturbed in their bitterness.

"The House on Prague Street" is about the senselessness of prejudice and the equal senselessness of responding to prejudice with hatred. And it's a story of that underrated quality: innocence.

Helene Richter, the novel's principal character and narrator, is about 10 years old, when changes begin to be forced on her family. Nazi soldiers have occupied Czechoslovakia, and her grandfather is forbidden to enter the park he founded in his hometown. Her aunt's house is confiscated "for the German Reich."

What was once an idyllic life for Helene becomes one of constant humiliation. And one by one the members of her family succumb to hatred and resentment and fear -- all except Helene.

She is blessed with lingering innocence, an innocence more comfortable with affection than with hate. And because of this she remains remarkably untouched by the horrors around her.

The book is filled with precise and powerful images. Demetz is particularly effective in evoking familiar emotions. "The House on Prague Street" sticks with you long after you've closed it, leaving the impression that a life uncontaminated by hatred is perhaps the rarest jewel in the world.