Martha Changes Her Luck is an episode of Martha Speaks, which comes after Martha Gets Spooked
It begins with Helen Lorraine and Carolina walking along the street to see a movie about a curse. Martha thinks it means bad words, but then it's explained what a curse is. The girls then give up trying to go to the movies as there is a ladder in the way and Carolina thinks it's bad luck to walk under a ladder. Martha tries to prove them wrong but ends up covered in green paint and having to take a bath. This convinces Martha that walking under ladders must be bad luck as she doesn't like baths, but Helen says that Martha had a bath because she got covered in paint, and she got covered in paint because she bumped the ladder and knocked down a paint can. Martha gets out of the bath and gets dried, but then breaks a mirror, which Carolina thinks is forty-nine years of bad luck.
At the cafe, Martha thinks she is doomed, but Helen tries to share her sandwich with Martha. However, Skits gets it first. Carolina goes off to play with Jake Lorraine. In the garden, Martha is moping. Then, T.D. comes on his bike with a kite, and Helen explains that Martha thinks she's cursed. T.D. explains that when he had tonsillitis, he had bad luck, but got good luck after he had an operation. Helen says that was a coincidence, and says that an example of a coincidence is thinking about ice cream and then an ice cream truck appears, but then an ice cream truck does appear. However they have no vanilla ice cream, only chocolate which the children liked, but it was like poison to a dog. Martha thinks it's because of the bad luck. T.D. tells about a character in a movie he saw who got so jinxed it rubbed off on everyone else and this scares Martha because she doesn't want to live in a cave and she runs away. One her way, she notices that Mariella's flowers have wilted, Danny's bus has a flat tire, Jake has fallen over, and Carolina has stepped on a banana. Helen feeds the dogs but notices Martha is missing. Martha is walking down the street, noticing that a car has almost crashed, a waiter has dropped a bunch of dishes, and a boy on rollerskates has fallen over.
At home, the Lorraines (minus Helen and the dogs) are watching something funny on TV. Helen goes off on her bike to look for Martha. Then, it starts raining. Helen finds Martha and explains that the bad luck was just a lot of coincidences, Mariella's sprinklers weren't working, Danny had run over a nail, and babies fall down all the time. They then get ice cream and go home.