In this sentimental comedy, Carol Reed tries for a bit of neo-realist whimsy that takes place in the London slums of Petticoat Lane. The film centers upon Joe (Jonathan Ashmore), a six-year-old London East-ender who believes strongly in the magical power of unicorns. Joe and his lonely mother Joanna (Celia Johnson) live with wily, philosophical tailor Kandinsky (David Kossoff), who convinces Joe that if he could only come upon the legendary unicorn, he could grant all the wishes of his poor neighbors. Taking Kandinsky at his word, Joe searches the slums for a unicorn. Then one morning, he finds one. Only thing is, it is not a unicorn but a baby goat with a growth sticking out of his forehead. Nevertheless, Joe is convinced that the goat is a unicorn. He gives an elderly homeless man all of his savings for the kid and triumphantly takes it home. Hoping to use the kid to grant all his friends' wishes, he hopes to grant the wishes of Kandinsky, who wants a steam-pressing table, and Sonia (Diana Dors), an attractive blonde who wants to marry Sam (Joe Robinson), a handsome wrestler. And finally, he wishes for his father to return home to his lonely mother.
~ Paul Brenner, All Movie Guide