- "We helped you, so you have to help us."
- ―Frankie to Thomas, Journey Beyond Sodor
When Thomas arrives at the Steelworks, looking for Bridlington Goods Yard to deliver his trucks, Frankie, along with Hurricane, patronise Thomas so he would not leave them and that he could take a look inside the Steelworks. They begin singing about how exciting the Steelworks is and try and persuade Thomas to stay there. Their singing makes Thomas feel excited about being there, and they even get him to agree to stay there.
The following morning, Frankie and Hurricane soon put Thomas to work by convincing him that because they helped him, he should help them in return. Thomas sets to work carrying molten slag out of the building and to a pit. Frankie agrees that he is very good at it, and says that he is her favorite new engine.
Eventually, Thomas starts to feel tired, but Frankie is pleased that Thomas is there because now she and Hurricane can do more deliveries. By now, Thomas wants to go home, so Frankie, again, convinces Thomas that because he helped them, he must stay and continue to help them out, and they leave him all alone in the Steelworks.
Thomas finds what he thinks is a way out, but he ends up derailing on some old and unused track. Soon, Frankie and Hurricane come to his rescue, both disappointed that he tried such a stunt. Frankie scolds him about what would happen if he were to leave the two of them to do his work when they have other jobs to do, and Thomas is brought back to the Steelworks. Later that night, Thomas again tries breaking out of the Steelworks, and he rams some flatbeds into the gate. The sounds wake Frankie and Hurricane up, and they immediately tell him to stop, but Thomas breaks through the gates and rushes away, and she and Hurricane chase after him. Thomas escapes onto an old, overgrown siding, and evades them.
Thomas is finally on his way home when he encounters a large, intimidating rolling gantry crane named Beresford, and then he sees Frankie and Hurricane approaching him again. Thomas manages to get Beresford to hide him, but he then overhears Frankie and Hurricane talking with James. Thomas realises that James will be held prisoner by them just like he was, and he realises he must help his friend.
Back at the Steelworks, Frankie and Hurricane try to convince James that the Steelworks is the place for him with their singing, but James isn't convinced and demands to know where Thomas is. They pretend they do not know him until James points out that Hurricane had delivered his trucks. They realise that James had seen through their fib, and admit they do not know where he went, but when James says he must go find him, Frankie again lies that he was coming straight back, and they make him stay and get to work.
When Thomas returns to the Steelworks with three experimental engines named Lexi, Theo, and Merlin, Theo and Lexi provide a distraction to draw Frankie and Hurricane out of the Steelworks, and this allows Thomas to slip inside unnoticed. However, Frankie and Hurricane are not taken by the distraction, and then they notice Merlin trying to sneak inside the Steelworks to help Thomas. They follow him inside, and they then see Thomas trying to convince James to leave with him.
Seeing their two "friends" betrayed them, Frankie and Hurricane begin forcefully attempting to make Thomas and James stay. Frankie runs straight up behind James in an attempt to derail him, but James narrowly avoids the impact. Frankie and Hurricane follow James inside and repeatedly try to stop him, but James keeps dodging their attempts. Thomas and Theo clear James' track while Lexi and Merlin block Hurricane and Frankie inside, and James manages to escape the building, but the trucks Theo was pushing hit a control panel and a magnet picks Thomas up, suspending him over a vat of molten slag. Theo tries to get Thomas down, but Thomas is dropped towards the molten slag, only to be knocked away by another bucket at the last minute. Thomas hits some more ladle trucks, and the slag pours onto the floor, dangerously close to Thomas. Hurricane rockets to Thomas' rescue, shoving him out of the way of the slag, but his wheels are caught and begin to melt. Frankie is horrified as she does not know what to do, but thankfully, Merlin shoves Hurricane out of the slag, saving his life.
Frankie is now very unhappy, as now Hurricane is out of commission and she is left alone. James and Lexi scold her for all that she and Hurricane have caused, and Frankie begins to cry. Thomas sees Frankie's sadness and asks her what the problem is, and Frankie admits that she only wanted someone to help her and Hurricane, as there was too much work for just the two of them, and no other engines were available or even wanted to help them. Thomas gets her to stop crying by saying that he knows some engines who are free to help: the experimental engines. Although reluctant at first, Theo and Lexi, with some encouragement from Thomas and Merlin, agree to stay and help out, as does Merlin.
At the end of the movie, while Hurricane is having his wheels replaced, Lexi, Theo, and Merlin are all settling in with their new lives at the Steelworks, and when Hurricane is fully repaired, he and Frankie join in once again.
Frankie is a charming and intelligent diesel shunter who can be very comanding. A natural leader, Frankie actively takes charge of operations at the Steelworks. She can be scheming at times, putting on a front to try and manipulate others into doing what she wants them to do.
Frankie, however, is not mean at heart. She feels hard-done-by and rejected because there is more work to do at the Steelworks than there are engines to do it. She would love to be free to go off making deliveries with Hurricane, but feels the only way she will ever be able to achieve this is by tricking others into doing the work she doesn't want to do.
Frankie is based on a Hudswell Clarke 0-6-0 diesel shunter which worked at the Manchester Ship Canal. No. 4002 Arundel Castle, affectionately known as "Billy", is preserved in working order by the East Lancashire Railway Diesel Group. Sister locomotive No. 4001 Alnwick Castle is also preserved as a static non-operational exhibit at the Winfields Store site at Rising Bridge.
Frankie is painted teal and black with gold lining. She has red and gold nameplates on either sides and "M.S.C." written above her face. The number "4002" is written in yellow on her front bufferbeam.
- 2017 - Journey Beyond Sodor
She may appear in the twenty-second season.
- Frankie is the first engine of several things:
- The first female diesel engine in the television series since Mavis, and the first female diesel to originate in the television series instead of the Railway Series.
- The first main antagonist of a special who is female.
- The first antagonist whose intentions are not meant to be cruel or evil.