Arthur Darvill thinks the Doctor Who cast have "ownership" over their characters.
The actor - whose alter ego Rory Williams departs this weekend - has always appreciated the fact the production staff want his input into the show.
He said: "The longer you do anything, especially something like Doctor Who, you feel like you've got more ownership over it.
"We know these characters better than anybody. Directors come and go, so it's down to Karen (Gillian), Matt (Smith) and I to keep a consistency with it.
"What's so lovely is, the team that work with us - and we work for - is very trusting, and very open to our suggestions."
The cast are never afraid to speak out if they are unhappy with something.
Karen - who plays Amy Pond - added in their joint interview with Doctor Who Magazine: "It's really important to speak up if you don't feel that something's right.
Work through it till everyone's happy. It's important to to that."
However, Arthur admitted he worries he and his co-stars are a "bunch of idiots".
He said: "I do get concerned that we're just a bunch of idiots. We do express ourselves far better through song though."
Karen disagreed though, adding "I actually never get concerned about that.
"I like the games we play. And the singing. It's been a sing-y shoot."
Karen's Amy will also say goodbye in this week's episode 'The Angel's Take Manhattan', which airs on BBC1 on Saturday (29.09.12).