When last we saw DI Fred Thursday, his life was hanging in the balance having just taken a bullet in the line of duty. Endeavour fans were left wondering whether the sight of Thursday being loaded onto an ambulance meant that he wouldn't be back for the next series. And it seems that we weren't alone.

"Well, I first got the news that he was going to get shot when I read the script. And I did think that maybe they want to get rid of me. I wasn't contracted for another series," confesses Roger Allam. "But luckily, the makers of the show reassured me that they didn't want to get to rid of Thursday at all!"

Indeed, the new series of the ever-popular ITV crime drama sees Thursday back on the case. But it soon transpires that he's a changed man as a result of his experiences.

"Yes, during this series, Thursday gets a bit out of control," continues the actor. "The bullet in the lung has left him thinking about his mortality. Perhaps he's having flashbacks to the war too. And it does produce some violence in him, particularly when his family comes under threat in the final episode."

So is there a feeling that Thursday has perhaps returned to work too soon and that, by doing so, he's opted to ignore some deep-rooted problems?

"Well, for soldiers and people who've lived through terrible violence, I don't think it ever leaves you. Whether you've had counselling or not. It can be very depressing and you can try and resist it and ignore it for years, but it'll always come back.

"For instance, I remember teachers at my school who'd fought in the Second World War. There was one in particular who made us listen to Churchill's funeral through a double period. And he just sat there looking into the distance, lost somewhere in his memory. So I often think of him when playing Thursday."

As for the future for Fred Thursday, viewers will soon find out that the bullet has done lasting damage to the no-nonsense DI. But he stoically (or perhaps foolishly) chooses to ignore the threat by ploughing on with his crime-solving. But look out too for a subtle shift in the relationship between Thursday and his protege Endeavour Morse as the series progresses.

"There is a sense that their relationship has become slightly reversed because we see Morse looking after Thursday. He tries to calm him down and stands up to him when he's wrong," says Allam. "In the past, Thursday has always been a bit of a father figure, but now Morse has to father Thursday."

The third series of Endeavour begins tonight on ITV at 8pm.