The Partridge Family discovers that during the night someone has entered their house and burglarized their TV, radio and stereo. As a gift Reuben has a burglar alarm installed in the Partridge home. It has sensor pads in various places under the carpeting – one step on a sensor and the house is filled with a heart-stopping, loud, clanging bell. While the Partridges are trying to adjust to the alarm and remember to turn it off when they are in the house, the neighbors are getting more furious each time it is set off accidentally. Petitions are being signed asking that the alarm be removed. When Shirley goes to the garage to shut off another """"false alarm"""" she finds Morris Dinkler, an escaped-con who holds the Partridge family and Reuben hostage. He purposely chose their house because of the alarm, knowing that new alarms are frequently set off by accident and after awhile the police don't bother to come. Everyone assumes the bulge in Morris' pocket, which he refers to as """"Big Bertha,"" (thetvdb.com)