After five seasons and what will be exactly 100 episodes, the Fox series Fringe will come to an end Friday, January 18 with "Liberty" at 8 PM ET, and "An Enemy of Fate" at 9 PM ET.

John Noble has been there every step of the way as Walter Bishop, a character who started this journey as a mental hospital patient in the pilot, and who now may save the world with his brilliant plan, when all is said and done. John Noble recently held a conference call, where he first spoke about how this was the first show he was on that required a long-term commitment.

"Doing something of this nature was new to me. I'd never done anything that required a five-year commitment. To build a show that seems to have kept the imagination of the world so much was a bit other worldly to be honest with you. I would go to anywhere in the world really and people would stop me in the street and talk about Fringe and how much they adored it and asked questions about it. The international reach of Fringe, I think, still catches me by surprise a bit at times. Also, I was given the gift of a character that is every actor's dream. So you combine those two factors and it's been an incredibly memorable five years."

He also spoke about the bond that formed between himself and his co-stars Anna Torv, Joshua Jackson, and Jasika Nicole.

"I guess because I'm the older fellow there I kind of think of them all as my kids in a way. I have a very special love for all of those actors and I'll miss them. Over the five years we were given the change to develop some pretty close bonds, both with our characters and personally, and we did. I don't really know how to explain it any other way than that. It's something that we earned over five years. It probably wouldn't have been there with two years, but with five years it was definitely and is definitely there. It's probably a life-long bond, I imagine."

The actor also teased that Walter will have to do something quite amazing to beat those bald-headed Observers in the series finale.

"We know that something radical has to happen in order to beat the Observers. I think by now we've built up to the fact that possibly maybe Walter has to do something pretty outstanding to make this happen. More importantly, I think, what you'll find is the way that his relationship with Peter plays out over the next two episodes, and in particular, the finale is really quite remarkable. That's something we had to do because we spent so much time and I know that the fans love the relationship between Peter and Walter so much and we certainly paid homage to that and brought it home, I believe, really strongly."

John Noble also talked about his initial reaction to the final script, and his last day on the set.

"I think we were all apprehensive to see what would happen in the finale. We didn't know until really quite late in the piece how Joel (J.H. Wyman) would finish it off. I can honestly say that it was everything that I had hoped it could possibly be. When I read it I thought that he had done a masterly job in writing in, tied up our character lines, tied up the great story arch. I couldn't imagine a better job, to be honest with you. So I was extremely elated when I read the final episodes. The last day on set was really quite fun. We were all kind of buoyed up. It was one of those nights that go forever. I think we finished at 9:00 in the morning or something, but we had a lot of fun. I can remember we all got a fit of the giggles halfway through the night, which is probably really inappropriate. All of us were doing a scene together. I don't know. It was just hilarious. I couldn't get my lines out, which is very unusual for me. I just kept getting it wrong and we were all laughing a lot. But it was good fun. We had a wonderful time. The last scene I did was a beautiful scene with Michael Cerveris, but backstage all the rest of the cast were on set as well, as we do in most scenes. You give your speech afterwards and so forth. I felt really buoyed up afterwards. I didn't feel depressed. I thought that we'd really had a great finale. The last day was so much fun."

The actor actually played several different versions of Walter Bishop, in various timelines and alternate universes throughout the course of the show. He spoke about how challenging and exciting it was to play multiple versions of the same man.

"Going backwards, the pure fun was the original Walter, who was just released from a mental institution and probably shouldn't have been. He was just fun because he could basically say and do anteing and get away with it. The most difficult Walter was the one that I had to play when there was no Peter in the world. That was really tricky. I think it was the beginning of Season 4. It was really tricky to play that same character but without the relationship with the son redeeming himself. He wasn't a well fellow. I mean I played him with a lot of OCD attributes. He really wasn't a very pleasant man. I found that one the most difficult to play. I loved playing Walternate because he was the same character actually, completely the same character, version 1985 and then it developed in such a different way physically and mentally. So to be able to play that in the same television series as playing the other ones was a fantastic gift to me."

Find out how Fringe wraps up its final season Friday, January 18 with "Liberty at 8 PM ET and "An Enemy of Fate" at 9 PM ET.