Lucy convinces Mr. Mooney that she's too ill to come to work so she can go to a department store sale. After examining some of the items for sale in the store (and causing a lot of damage), she learns she is the ten-millionth customer and wins many valuable prizes. One prize she wins isn't one to her liking - her photograph will appear prominently in the next day's morning newspaper. Lucy goes to great lengths to make sure that her boss doesn't see the incriminating photograph and fails miserably.
A European movie company fronted by a famous French movie actor comes to Los Angeles to set up shop. Mr. Mooney's plans to land their account are nearly scuttled when Lucy becomes inebriated on French champagne.
Lucy tries to convince Jack Benny to take his money from his underground vault and deposit it in Mr. Mooney's bank. She plans to do so by designing even more elaborate precautions than Benny's own booby-trapped passages.
After there is a 48 cent shortage at the bank, Lucy puts her own money to make the difference. When Mr. Cheever finds out, he blames Mr. Mooney, and Mooney is promptly fired. Lucy becomes Mr. Cheever's secretary, but feels so bad about Mr. Mooney, that she tries to convince Mr. Cheever that he's going insane because of the guilt of firing Mooney, and she plots to get Mr. Mooney's job back.
Lucy accidentally tears up a letter from someone who is coming to visit her, not knowing when or who is coming to stay. It turns out to be Lucy's very controlling Aunt, who changes Lucy's diet to disgusting diet food, and gives her daily exercise regiments, so Lucy plots to get rid of her.
Lucy takes in a homeless man and feeds him a home cooked meal. When she finds out that he needs a job, she goes to Mr. Mooney for help. He wants nothing to do with it until he finds out a millionaire is going around and posing as a bum and handing out cash to people who help him. So Mooney promptly gives him a job and a place to stay at his home, not knowing that the man is simply broke and not the secret millionaire.
Lucy injures her leg while working at Mr. Mooney's house, so she hires Mary Jane's lawyer cousin to get a little money for her pain and suffering. Once shady Willy Wiley sees big bucks to be made, he sues Mooney and the bank for everything they're worth.
Lucy visits a local pool hall and enters their billiards tournament. Her main competition is a woman named Laura Winthrop. Cigar-smoking Laura, however, looks suspiciously like a a pool hustling man named Ace.
Lucy becomes a trainee flight attendant for Trans-Global Airways. She's teamed with fellow trainee Carol Tilford, who's afraid of heights. On their very first flight, the movie breaks, leaving the two to entertain the passengers.
After Lucy breaks her leg, Mr. Mooney enlists the help of Lucy's best pal Vivian Bagley from Danfield to take care of Lucy. Then, the two start reminiscing about old times and the crazy things they did together.
Lucy borrows Mr. Mooney's TV set and promptly breaks it. To make enough cash to replace it, she moonlights as a carhop at a drive-in. While there, she takes up the cause of a young motorcyclist who's accused of stealing and stripping cars.
Mr. Mooney flirts innocently with a waitress when attending an out-of-town bank convention. But then the sexy server comes to L.A. insisting that Mooney has proposed to her. To scare her off, Lucy pretends to be Mrs. Mooney and shows the homewrecker how horrible it is to be married to a such a monster.
When Lucy takes Mr. Mooney to buy a fur for his wife, they're made an incredible offer by a shady character. The stole they buy from him turns out to be "hot", getting the two of them arrested for possession of stolen goods. Lucy and Mooney's schemes to get his money back from the crook get them arrested again... and again.
Lucy brings a Drunken lounge singer home to sober up for the night and finds out that he was once a talented song writer who is now a has been. He plays for her a song he's been writing and Lucy swears it's a hit, so she helps him make a come back.
Ken is turned down by Mr. Mooney for a loan to open his dance studio. Lucy decides all he needs in a little publicity so she arranges for a bunch of truck drivers to sign up for lessons and wrangles some TV coverage.
Lucy and Vivian's (who's visiting Lucy) car breaks down in the middle of nowhere. They walk to a house down the road to see if they can call an auto club and the house is owned by none other than Joan Crawford, the movie star. All her furniture has been sent out for cleaning, so Lucy and Viv think she's broke and try to raise money for the star.
Sid Caesar enlists Lucy's help in capturing Frankie the Forger, a look-alike who's passing off bad checks in his name. Lucy becomes confused with too many Caesars running around and repeatedly captures the real Sid.
Mr. Mooney wants to be named president of the San Fransisco branch of the bank. To get the job, he enters his boss, Mr. Cheever, in a Boss of the Year contest and writes a ridiculously fawning letter comparing him to Abe Lincoln. Meanwhile, Lucy does the same thing and enters Mooney.