She was described by others as: "a superhero; she wants to save the world. The only problem is Polly is young, idealistic and needs to learn that the world is a complicated place and not everyone wants to be healed."
Di Martino had previously appeared in supporting roles in both Casualty and spin-off Holby City. She auditioned three times for the part, and had to cease studying for her Masters degree in Applied Theatre when cast. She commented on her casting: "I feel very lucky to be joining such a long-running and well-established drama. I'm looking forward to Polly bursting onto screens, and hope viewers find her as much fun as I do." Series producer Oliver Kent added: "Sophia is a brilliant actress and we're very excited that she's joining us. We can't wait for the audience to see her - they're going to love her." Di Martino describes Polly as "very optimistic. She sees the best in everyone. She's fun, opinionated, brave and sometimes gets a little bit too close to her patients." After the suicide of homeless man Alistair MacCormack, who was infatuated with Polly, Polly was suspended while a full inquiry into his death was undertaken, after evidence given against her by Alistair's best friend, Abe, who believed that Polly should lose something that she really loved - her job - as revenge.
Polly, despite Abe's threat, keeps her job. It's revealed that she is in love with Jay and has a short fling with him. He quickly ends it, as he wishes to only be friends and because he still has feelings for Ruth. She was due to leave in April 2011 to become a counsellor after admitting that she would rather be helping those with psychological problems rather than physical. On her final shift, she was stabbed by mentally unstable patient Hannah Fleet, and later died.
Behind the scenes
- Although the episode that she died in aired on 30 April, the events followed on directly from where the last episode left off on 23 April, making that her date of death.