One of Chandler's duties at work is to fire a sexy co-worker, but he finds it very difficult to do. Joey meets Phoebe's twin sister, Ursula, and begins to date her, even though it hurts Phoebe's feelings. Ross, wanting to be a good daddy, goes to child-birthing classes with Carol and Susan.

Rachel injures her ankle, but since she has no health insurance, she & Monica commit an act of insurance fraud. They also manage to meet a couple of hunky doctors while at the hospital. Even though Joey blows off her birthday party, Phoebe still comforts him when his relationship with Ursula fall apart. Marcel the monkey gives Ross a scare when he ingests a few Scrabble tiles.

Why do some people crave chocolate? Why does music make some people cry at the movies? How did kissing begin? Mystery of the Senses, a five-part NOVA special airing over four consecutive nights, seeks answers to these and other questions as it explores the complexities of smell, taste, touch, hearing, and vision. In this exploration, series host and naturalist Diane Ackerman travels around the world to investigate the science, history, and cultural values that influence our senses.

Jerry gets in trouble with the doorman at Elaine's boss's apartment but was only trying to be nice. Kramer and Frank Costanza go into business together to help the manly breast problem that Frank has.

Benton pulls a 48-hour shift and refuses to sleep, despite Hicks's orders, which later proves disastrous for his mother. A doctor spends the entire day studying the ER as a model for a new hospital, and offers Susan a job; he turns out to be a psych patient who wandered downstairs. Jenn tells Mark she wants a separation. Doug treats an abused young girl, and Carol receives bad news about her attempt to foster Tatiana.

Beavis and Butt-head fall asleep on the couch. They sleep right through school, and have bizarre dreams where they are on various television shows, like Oprah, Star Trek, The Dating Game, and The Brady Bunch.