Girl meets boy, girl likes boy, boy turns out to be an angel.Therein lies the problem facing down-to-earth Meg Ryan in “City of Angels,” the new film from Warner Bros. Pictures.Ryan plays Maggie Rice, a practical cardiologist who thinks she knows the universal order of the world and the things in it. Her medical training alone is what saves people, and she fully believes this until she inexplicably loses a patient despite using all the right procedures.This, of course, leads to some deep questions no one can answer.Enter mysterious stranger Seth, played by the slightly slurring, low-voiced Nicolas Cage. Seth knows Maggie’s name on first meeting and pops up wherever she goes. He then identifies himself as an angel and, by so doing, brings even more questions into the already-troubled doctor’s life.While the overlying question of “What would you do for love?” seems a little trite, the movie’s more subtle issues are its real beauty.Which is the better world: one of no pain, no fear and no hunger, or one that allows you to feel another’s touch and taste the sweetness of a pear? As one character says, “What good are wings if you can’t feel the wind in your face?”Yet, how often do people take what they have for granted and wish to be something they are not? Few, if any of us, can deny wishing for things like more money or great beauty, but each “perfect” situation brings its own disadvantages that we don’t always acknowledge.Ryan gives a believable performance as a woman who is suddenly presented with the image of what she’s always denied: namely, the existence of something greater than humankind. Subduing her usual perkiness, she takes the viewer through her feelings of disbelief, curiosity and finally acceptance as her black and white world turns a decided shade of gray.Cage also truthfully portrays the angel who asks the kind of questions we’ve come to expect of a heavenly being. Yet when he asks Maggie how she can be so sure there is no higher power, it does not seem like just transcendental contrariness. He asks because he longs to understand the experience of being human, of something he has never been able to be.Dennis Franz, of “NYPD Blue” fame, brings the required comic relief in the everyman guise we’ve come to expect from him. He and Andre Braugher, who plays the angel Cassiel, also share the function of sage counsel.Franz’s character claims no one believes in angels anymore, and maybe he’s right. However, seeing the leagues of celestial messengers in “City of Angels” use their invisible presence to guide us, that disbelief is easily suspended for at least two hours.The two hours also show the truth of Seth’s statement. “There’s so much beauty up here,” he says, while sitting on a stories-high billboard and viewing the city from a distance.But there’s also so much beauty down here.