Saturday night in Cambridge: the lid's off--that is, till twelve o'clock. A week of regimented hours--nine to five for the salesgirl; afternoon labs for the chem concentrator--fades into the past. And only the night remains--one sharp, clear moment filled with the smile of girls and the hurry of feet. The Square is a whirling top. Buses are leaving every minute: what will you have? The world is yours: Zero Hereford, The Folies Bergere, or just Belmont. Traffic on Boylston Street is stalled. Blow your horn, blow: Saturday night waits for no man. A car radio is shrilling: "At the Balalaika, who knows what mystery tonight may bring?" Who knows? Around every corner, around every smile is mystery.

By 9:45 long, sleek care begin to draw up in front of Brattle Hall. Sometimes a chauffeur opens the door: sometimes an undergraduate whose sloppy reversible contrasts oddly with his white starched shirt front and pearl studs. The girl is in shimmering silk: it is the very latest thing, the very best. For this is the night, you know. The third in the Brattle Hall series for sub-debs.

Just inside the door the girl gives her name to a man at the desk: he checks it off carefully. Few girls not on that ancestral list ever get on the dance floor. You are "cut in" quickly; but it soon becomes as convenience. There is little to talk about. You begin on her school, but after you have learned that she goes to Miss May's, Beaver or Winsor, conversation is over. In the fall you might ask her about field hockey, in the winter about the school play. She has probably taken a weekend to New York; but she can tell you nothing about the Nine O'clock.

At 11 supper is announced; a half hour of intimacy, a chance to laugh over the last issue of "The New Yorker" or Monday night's opening. But she knows nothing of cither. Oh well, she was at the Somerset last week. Why not talk about the music--but it's always Ruby Newman. Still, her hair is soft and hangs enticingly around her neck. Talk about telephone numbers about hers in particular. She is nervous about giving it.

And then it's midnight: cinderella-time in Boston. A policeman stands ready at the door; the blue law in action. Good night, sweet ladies. Ta, ta. See you at "The Eliot" next week. "It's costume party. Won't it be exciting?

Suppose you got on the Mass. Avenue bus instead of going to Brattle Hall. You couldn't miss the Tech Roller Rink; the air is crowded with laughter, and the whine of skate wheels on wooden floor. At first your skates don't seem to go in the right direction; you stumble. Your hand reaches out to steady yourself, and finds another hand in it. Funny, you never think to ask Why. She is there, and that's all, skating with you. She has brown hair tied back with a ribbon and a trim green dress. You are both talking at once; you have so much to say. Just as though you have known each other for years.

Here name is Alice, and she works in a Cambridge factory--it doesn't matter. Only her smile have so much to say. Just as though you had matters. There are hundreds of other couples skating together. There are one or two sailors; but most of the men are in shirt sleeves. At the end of each dance the music stops, the couples break apart. But Alice stays with you.

Walking home, you mention music, and she begins to babble about Tschaikowsky. She plays it so much that her four year old nephew has learned to pronounce the name. She lives at the Newtowne housing project. Standing in the clean, wide court the wind catches her hair and makes it dance. And then you ask her (without ever thinking) about Monday night? Alice nods; Saturday night is over: Monday night will soon be here.