Luka is the son of Tom Franklin. During his first appearance, Luka realizes that his father is not doing very well at work, including when he makes the Franklin's Cube, a call tracker. So, he decides to help. After Tom gave free quotes to all his clients, Luka took the list of everyone and started hoaxing people to buy the Franklin Cube, and among those people are Ezra, Ms Maniaci, Toby, Mr Quinn and Belinda in the green house. The moment he passed the prank calls, Luka sneezed and sniffed, and many thought he had the flu, but in fact, he is allergic to cats, mainly due to the fact that the cat that follows Jack all the time appeared there every day, the that generated these sneezes.
However, his actions created suspicions for Mrs. Maniaci, who started to think it was Ezra and this made her accuse him in front of Maudie without evidence, however, Maudie manages to get her suspicions about him. So, Maudie discovers that the person who did this is a person from Tom's Store, where she reveals that it was Luka, because he is always in the store, and Maudie reveals to others that he is allergic to the cat, and not flu, where he thought about it when Ezra mentioned that Tom said they were allergic to the cat, however, Jack was with the cat, and Tom was not having an allergic reaction at all, and so he was referring to someone else. To prove it, Maudie interviews Luka, introducing herself and saying that it was she who answered Ezra's cell phone on Thursday, but Luka corrects it, which proves that he was responsible and he was shocked, and at the same time, afraid of his father finding out. So, he goes outside with the group and reveals that it was him. Ava confronts him, saying that this was very rude and that he cannot force someone to buy something that he is not interested in, so Luka apologises, and Ava suggests a stall outside the store to demonstrate the Franklin Cube, where he is a huge success, and both Luka and Tom are happy about it.
|1. "The Case of the Curious New Girl":||Absent||11. "The Case of the Suspect Sprinkler":||Absent|
|2. "The Case of the Disappearing Deliveries":||Absent||12. "The Case of the Peculiar Pop Quiz":||Absent|
|3. "The Case of the Missing Solar System":||Absent||13. "The Case of the Science Sabotage":||Absent|
|4. "The Case of the Distressed Dancer":||Absent||14. "The Case of the Wrecked Rehearsal":||Absent|
|5. "The Case of the Sleepover Secret":||Absent||15. "The Case of the Perplexing Painting":||Absent|
|6. "The Case of the Big Mouth Challenge":||Absent||16. "The Case of the Turtle Thief":||Absent|
|7. "The Case of the Pestering Prank Caller":||Debut||17. "The Case of the Misplaced Mug":||Absent|
|8. "The Case of the Spoiled Sports Day":||Absent||18. "The Case of the Sad Little Sister":||Absent|
|9. "The Case of the Exciting Excursion":||Absent||19. "The Case of the Disoriented Drone":||Absent|
|10. "The Case of the Very Lost Notebook":||Absent||20. "The Case of the Baffling Birthday":||Absent|
|Main||Maudie Miller · Ezra Banks · Ava Andrikides · Kyle Klimson|
|Recurring||Miss Tan · Mr. McGillick · Mrs Parides · Mr Barker · Poppy Banks · Justin · Caitlin · Mario · Pixie · Amelia Fitzgerald · Ruby · Esther McCarthy · James · Diet · Toby · Miranda · Archie|
|Guests||Billy · Sophie · Grace · Oliver · Joanna · Zac O'Halloran · Trish · Terri-Anne · Ebony · Claudia · Chuck · Hayley · Tall Girl #1 · Tall Girl #2 · Small Boy #1 · Small Boy #2 · Ben · Tom Franklin · Luka Franklin · Jack · Ethan McLaughlin · Ray · Mr Henderson · Jenny · Kelly Pickett · Dayani · Abby · Paul · Xavier · Kevin Milosec · Annie · Frank · Pip · Bella · Jayden · Judge · Tiana Jonhson · Ryan McCulloch · Chloe McCulloch · MacKenzie · Violet · Milo · Miss Ramsay · Zoya's Father · Kate · Angus · Evan · Owen · Coach · Savannah Gonzalez · Mayor · Emma · Dionne · Waiter · Rosemary · Butcher · Sylvia · Patrick O'Leary · Duncan Kent · Charlotte · Charlie · Lexy · Ally · Elijah · Dana · Cole · Gary · Sadie · Kyle's mum · Harriet Jacobi · Jordan · Natasha · Ramona · Small Boy · Sarah Banks|