Brace yourselves Holby fans... Zosia Self is back! But it seems she might be keeping a secret about her time in the US, as Camilla Arfwedson reveals...

Camilla Arfwedson on Zosia’s shock return to Holby City…

Welcome back to Holby! What prompted you to want to return as Zosia?

“I always thought it was never really over for Zosia as in I don’t think she ever really left for good. The idea was that she was going to go to America for six months, spread her wings and challenge herself, which she’s done. I certainly wanted to revisit her just over a year later, so I thought it was probably about time to come back and see where’s she’s at!”

Zosia’s return in next week’s episode involves something of a ‘guess who’ scenario…

“Yes, it’s really fun, I loved filming that actually. You can’t tell if it’s Zosia or not… then there’s this big reveal. I don’t know if the audience are going to know it’s me but I like the idea that it’s kept secret until that moment.”

Jac Zosia Zosia's return Holby

Frenemies reunited in Holby City? Zosia and Jac are back working together on Darwin…

Jac’s expecting a mystery locum registrar… so she’s stunned when Zosia turns up in theatre. Is Jac pleased to see her?

“Not exactly. Jac bristles the minute Zosia walks through the door and there’s some obvious animosity there. But Jac’s hostility comes from wanting Zosia to do well. Rosie and I are actually really good friends in real life, which makes those scenes even more fun to play.”

Later, Zosia tells Jac the job in America just didn’t work out. But Jac obviously doesn’t believe her…

“Jac can’t believe Zosia had this great opportunity in front of her and now she’s packed it all in and come crawling back to Holby.”

Do we find out anything about Zosia’s time in America at this stage?

“No. Zosia holds her cards very close to her chest about her time in America and about why she’s really back. She tells Jac she just wants a job.”

Holby City Zosia March

Zosia claims she just wants a job… but what’s she hiding?

Knowing Zosia could work anywhere in the world, however, Jac refuses to hire her. But Jac’s soon forced to bite the bullet and she hands Zosia a contract to sign…

“Zosia basically hoodwinks Jac into becoming her new registrar. As soon as she’s signed the contract, Zosia drops a massive bombshell. And let’s just say Jac’s not very happy about it!”

Watch Zosia’s return on Holby City, Tuesday February 19 at 8pm on BBC1.