Bon Voyage, Charlie Brown (and Don't Come Back!) 1980 ( 6.4)

Charlie Brown, Linus, Peppermint Patty and Marcie travel to France as foreign exchange students. Also along is Snoopy and Woodstock. While everyone is excited about the opportunity to travel to a foreign country, Charlie is disturbed by a letter he receives from a mysterious girl from France who invites him as a her guest only to find that he does not seem welcomed to her Chateau.