Doctor Who will be introducing a new companion in its next season, played by star Varada Sethu. But, if you watched the latest episode, ' ,' you might have noticed a familiar face popping up quite early..

. , and, if you're confused about just what's going on, the team behind the sci-fi show have explained all. "It's a delight to welcome Varada to Doctor Who, earlier than expected, though things are about to get timey-wimey," .

"That's the end of Mundy Flynn's story, so quite how Varada returns will be revealed next year." Sethu herself has also addressed her appearance. "I'm so excited the world has finally met Mundy Flynn, it was such a joy to take my first spin in the Whoniverse!" she said.

"I'm so grateful I get to come back for more, but you'll all have to wait and see how that manifests in the new companion role." If these teases are just too mysterious for you, though, 'Boom' writer Stephen Moffat shed more light on the situation. "We’re just doing it again," he told , referring to Jenna Coleman appearing early in the show before Clara Oswald officially became companion.

"I mean, I was talking to Russell [T Davies, showrunner] about what we're going to do, but she's there! We're just going to do Clara again. So it's fun, isn't it? It wakes you up. You think, 'Ah, there she is!'" Beyond that, though, Moffat wouldn't be drawn on the mystery.

"I’m going to say nothing about what's going on there," he said of Mundy Flynn's name. "You're not going to get nothing. It's Ru.