Frasier, Niles and Martin assist when their cab driver (guest star Charlayne Woodard "Unbreakable") goes into labor. Afterwards, Niles contemplates fatherhood and decides to try Frasier's experiment to test his own paternal instincts. Also, Frasier accidentally puts a funny, but tasteless, birthday greeting on a co-worker's get-well card, forcing him and Roz to figure out a way to retrieve the potentially-embarrassing message from the man's hospital bedside.