Introducing themselves in the dark, stalled subway car: Susan and Hal Hunter and their Answer Man classmate from White Plains, John Kent Haven; well-dressed, well-spoken light Negro Terry Mcllvaine from Mt. Vernon: diffident Cecilia Lopez from the Bronx: the girl with glasses and dark stringy hair, Jennifer Morgenstern from Yonkers; and talking but not going to the TV science program, Dobbs Henry and James from Harlem. . . ""Sure 'nuff? Harlem? -- Sure 'null."" Too late now for the show, the six with tickets agree to go together the next Saturday. What follows are salient moments from the week of each: Terry's sense of being an exception: John wishing that he could communicate with people: Hal reminded that some close to home need help; Jennifer reassuring her mother who relives Nazi persecution that it needn't happen again. Telling herself so because she's read in the paper that James, the bitter one, has been shot fleeing from a theft he didn't commit. And Cecilia's father has been run over and Dobbs Henry's family has been evicted. . . and you do give a damn about all of them because it rings true. Which is why the climax togetherness on TV -- seems a sop; fortunately there are a few days with honest James in the hospital afterward. Except for an earlier socio-log on him (and the foregoing), this is spare and straight: Dobbs Henry and his family talk Harlem shorthand, Mrs. Morgenstern speaks like a German refugee, everybody says what he thinks (not always aloud). There remains the recurrent question of ready-mixes that are also time capsules: today's relevance may be tomorrow's retrospection but why worry if it works as fiction, and not without laughter.