Lucy tells Ethel all about the schedule for the European tour. She also mentions that her mother in going to stay with Little Ricky while they are gone. Currently Mrs. Mcgillicuddy is taking an auto trip through New England but is going to be in New York the day before they leave. Fred brings up his old vaudeville truck so that Ricky can pack the band uniforms in it. Ricky comes home with the boat tickets and reminds everyone to get their passports. Lucy gets a phone call from the Jamestown Hall of Records saying that they can't find her birth certificate. Ricky suggests calling her mother but Lucy starts crying because she knows that her mother can't be reached.
To get her passport Lucy needs to find two older friends who knew when she was born. She calls the Jamestown Hall of Records in hopes of finding someone that she knew. She also calls the doctor of delivered her and tries to locate an old babysitter.
When Lucy does meet with Helen Kaiser, her old babysitter she runs into a snag. Helen's husband Sydney, a lawyer insists on looking over the paperwork Helen needs to fill out. It ends up that Helen has been lying to her husband about her age and even goes as far as to say that Lucy was her babysitter when she was little. Lucy leaves in a huff still needing another signature.
Desperate for any way to go to Europe Lucy decides to try and stowaway in Fred's trunk. She fits perfectly with the door open. She then suggests that Ethel close the trunk. But when Lucy starts to panic Ethel can't open the trunk because Lucy has the keys in her pocket and she can't move her arm to get it out. Ethel goes looking for Fred to try and get her out. Ricky comes home unexpectedly with Marco, the piano player. Ricky uses the trunk as a drum not knowing that Lucy is inside. Ethel comes running back after they leave mentioning that she can't find Fred.
Dr. Peterson, the man who delivered Lucy comes over to sign the paper. He thinks that Ethel is Lucy. Lucy does everything that she can think of to prove to Dr. Peterson that she really is Lucille McGillicuddy. Together they sing "Skip to my Lou" because Dr. Peterson taught it to her. Ricky comes home to see Dr. Peterson, a man he doesn't know dancing in his family room and a hears a voice coming out of the trunk. Fred brings a crowbar and with Ricky's help open the trunk. Dr. Peterson mentions that Lucy wasn't born in Jamestown, she was born in West Jamestown. A telelgram arrives from Lucy's mother and enclosed is her birth certificate.