Mr. Kotter takes the sweathogs on a field trip to a museum. Mrs. Kotter and Mr. Woodman are along as chaperones. They meet the unusual museum curator Mr.Gore (John Astin) who seems odd and superstitious. In the Egyptian display, he warns them of the mummy coming back to life if they joke and kid around. Naturally, the door shuts itself and everyone is trapped. They humorously begin to panic and make attempts to get out. Epstein manages to get the door open. (thetvdb.com)