Endeavour is back with a series that sees Shaun Evans play out some ambitious storylines as the newly-promoted young Inspector Morse. The actor tells Georgia Humphreys what fans can expect, from romantic developments to big changes in the police force

THERE'S no denying Inspector Morse was a mighty success. One of British TV's greatest detectives, the final episode of the crime series, starring the late John Thaw, was watched by more than 12 million people in the UK.

And when the prequel to the show, Endeavour, hit our screens over a decade later, it gave fans the chance to see new sides to the cantankerous yet endearing character.

In the fifth series of the ITV drama, once again set in Oxford, we find out more about his relationships with the opposite sex - and while former love interest Joan Thursday is still part of the story, new characters come on to the scene.

"There's a little bit of action," discloses Shaun Evans, the actor behind the young Endeavour Morse. "Not before time, if you ask me. His relationships with other women show a slightly more rounded version of the character. I think it's okay to surprise people."

The new series begins with Morse being promoted, after finally passing his sergeant's exams. But he's not feeling entirely satisfied with the new role.

"It hasn't been anything he thought it would be," 37-year-old Evans explains in his thick Liverpudlian accent. "There's a line Morse says to Dorothea Frazil, 'It's just the same, but more work'. Belligerent to the end."

There are further issues to come where his job is concerned - the force is facing some changes. In 1968, Oxford City Police, along with Oxford County and two other local constabularies, ceased to exist when they were merged into Thames Valley (Morse fans will recognise that name, for sure).

And the station closing has been the main focus of the story this time, says Evans. "Some of the older generation don't know if it is going to be their last case," he continues, before revealing: "The way we have ended it is that each of us get a letter saying where we are going to be posted."

Work woes aside, there's one person in Endeavour's life fans particularly want to hear about. Over the previous series, we have seen his relationship with Joan Thursday - his boss' daughter - go through some serious ups and downs, including her turning down his marriage proposal. Now we see him look for love elsewhere, even if Evans admits his character still holds a torch for Joan.

"I think it is tricky because you can't keep doing the same thing," he says. "You have got to try to do something new and take it to somewhere new and that has got to be in the relationships, whether that is with Joan or with someone else. His involvement with other women is a subconscious knee-jerk reaction to the history between him and Joan. He's trying to find his place in the world and who he's going to spend it with."

So, what romantic storylines can we expect? "There is a brilliant French actress in this series; she plays a character called Claudine, a photo journalist," the actor says.

But while he shares there are a few intimate scenes coming up, he adds: "This is a family show going out at 8 or 9 on a Sunday night, so you are not going to be rolling around with your kit off!"

If there's one thing that hard-working leading man Evans brings to every scene in the show, it's energy. Asked where that comes from, he says: "It's sobering knowing that a good number of people are going to be watching it on a Sunday night.There is no point in being lazy. I also think if you are being asked to return to something, you have got to make it good and there is so much brilliant TV out there and so many brilliant stories being told, you haven't got time to rest on your laurels."

Evans, understandably, feels very lucky to play the role and an undeniable element in the show's ongoing success must be that the character was already so adored by TV fans. The original show, based on the popular books by Colin Dexter, who died last year, ran for 13 years.

"Colin was still in our thoughts as we made this series," says Evans. "We want to try and stay as true to his original vision as possible while also taking it in new directions."

While shooting six films for this series, rather than the usual four, has been a challenge, Evans reckons the decision has paid off.

"The conflict comes between quality and quantity,' he says. 'Is the budget going to stay the same? Are we going to be as ambitious with six as we were with four? Is the level of work going to stay the same standard? I am pleased to say I think it has, which is great."

We can expect some particularly ambitious storylines too, set in places such as a cinema and an army barracks, while one film even has a spy feel to it.

Asked what the future is for Endeavour, Evans says: "This series definitely sets up more for a return. There are lots of questions to answer. But there are also lots of factors involved. So you just take this job one day at a time."

The star, who would love to do more work behind the camera (he directed an episode of BBC One drama Casualty last year), insists he will know when the time is right to say goodbye to Endeavour.

"I think it has got a shelf life," he says. "I think the trick is to leave before everyone is sick of you!"

Endeavour returns to ITV on Sunday, February 4