Preparing for a Canadian tour the Family must have their birth certificates. The attic produces certificates for all except Danny; his is not to be found. When introduced to the Family, booking agent Marty Burns jokingly refuses to believe Danny is a Partridge, "not with that hair and those ears," and Danny is convinced he is an adopted child. Shirley tries hard to talk him out of his belief, but Reuben and the others, in trying to kid Danny about his origin, only confirm his opinion he is not a Partridge. At the hospital where all the others were born Danny finds there is no record of his birth. Heartbroken, he refuses to believe Shirley's story that he was born unexpectedly while the family was on a picnic and thus missed the "regular" hospital. On a return visit to the hospital Danny learns the name of the one male child born there on his birthday is a son to Mr. & Mrs. Young. (thetvdb.com)