It's the 1960s and actor Peter Purves - married to Gilly and with a young son - is battling to keep his head above water.

It's the 1960s and actor Peter Purves - married to Gilly and with a young son - is battling to keep his head above water. Then he wins a part in a series destined to become a TV classic: Dr Who.

This first edited extract is from his new autobiography Here's One I Wrote Earlier . . .

I BARELY worked for a few months - I think I may have done a couple of episodes of Z-Cars, but that was all, and Gilly and I continued to struggle to make ends meet. Matthew was now well past his first birthday, and was walking and growing and money was a perpetual worry for us. Thank goodness for the National Film Theatre, which continued to employ Gilly on a casual basis.

But then out of the blue, my agent got a call offering me a cameo part in Doctor Who. Richard Martin had been as good as his word, and had cast me, without an audition, as Morton Dill, an American Hillbilly visiting New York in episode three of The Chase. This was a 10-minute scene at the top of the Empire State Building, where a group of tourists are being given the guided tour. My character becomes detached from the group, in time to meet the Doctor and his travelling companions as they arrive in the Tardis. Later, I also meet the Daleks who have arrived in a pursuing time machine.

We rehearsed in a Territorial Army drill hall in Acton, and I loved every second of it. I got on really well with Russ (William Russell), and Jacqueline Hill, the two original cast members who became Bill Hartnell's travelling companions. Bill Hartnell himself was friendly enough, if a bit crotchety.

As I prepared to leave the studio, the producer, Verity Lambert, and the story editor, Dennis Spooner, came up to me and said how much they had enjoyed my performance and asked if I would like to join them for a drink. Nothing very surprising in that, but I was flattered to have been asked.

You can imagine my surprise when, after a brief moment, Verity asked if I knew that Russ and Jacquie were leaving the show in three weeks' time, and then hit me with the bombshell question. “We wondered if you would be interested in taking over!” I nearly dropped my pint!

Would I? I was absolutely staggered, and replied without thinking that I would be thrilled to take over. Out of the blue, and totally unplanned, I had gone in a moment from being a small part player to a regular character in what was to become one of the greatest cult shows of the past 50 years. The following morning Steven Taylor was born when Dennis took me through the character. The odd thing about it was that I was to appear in episode six as Steven, having just played Morton Dill in episode three of the same serial. A quick growth of a stubble beard and some make-up made me look sufficiently different and three weeks later I was a regular in the series.

For the first time in almost two years I had a job that was just like normal folk! I worked Monday to Friday week in and week out . . . on the Friday we would go into the studio and rehearse with the cameras.

Then with those rehearsals complete, there would be a break for the boffins to line-up the cameras, matching their pictures and output, and we were ready for a dress run. Into costume and make-up and the show was then performed as if it was the recording. Supper break came next and at about 7.30pm we would record the show.

Mostly we got it right, rather than the other way round. Not always, however, but even Bill Hartnell's script errors were transmitted as recorded - his most famous line ever, being “I am not a Dog, a God” in an episode of the Myth Makers about the siege of Troy.

The series took a break for the late summer, six weeks I think it was, and so we parted company after Galaxy 4. We returned in the autumn ready for another season and more fun. Or so we thought. The first series after the break was The Myth Makers. It was a stunning cast and the whole serial was the most exciting since I had joined the show but it turned out to be an unhappy experience for several reasons. Not least was the fact that we had a read-through of episode one and we got the three later scripts during the week, only to discover that Maureen's character, Vicki, was written out of the series at the end of episode four. She was to stay in Troy as “Cressida”. When she received the script, that was the first time she discovered her contract was not being renewed. No reason was given, it was a fait accompli and she had been allowed to go away for a six-week break without anyone informing her that she didn't have much of a job to return to.

The next serial was a massive 12-parter called the Dalek Master Plan, followed by The Ark, The Massacre, The Celestial Toymaker, and then The Gunfighters, where Innes Lloyd took over as producer.

I really liked Innes and thought we were getting on really well, so it was a surprise to me when we started rehearsing the next serial, The Savages, that he took me to one side after recording the first episode to say that he was sorry, but that they weren't going to renew my contract. It was a bombshell to me . . . Bill was absolutely furious - he really had stayed very close to me throughout the year and he thought I was indispensable to the show. Not only was I totally dispensable, but little did he know that his days on the show were numbered also.

There were odd jobs to keep the wolf from the door. Then came the phone call that changed Peter's life.

I GOT a telephone call from my former agent, saying that although they didn't intend handling this, they had a request from a programme called Blue Peter at the BBC. They wondered if I would like to go along to meet the editor, Biddy Baxter, and they gave me a telephone number.

As it wasn't a proper acting job, I wasn't sure I wanted to go for it, but in the end, I thought that it was better than nothing and I called the BBC. An appointment was made, and a couple of days later I turned up on the fifth floor in the East Tower at the concrete doughnut; the BBC TV Centre.

I was called into the office where I was surprised, first, to discover that Biddy Baxter was a woman. It just hadn't occurred to me that she was - apart from casting directors, every major player I had met so far in the business was male. I was also surprised to see how attractive she was, albeit with an overlying untidiness, particularly her hair, which was loosely tied up in a sort of bun. But she welcomed me gushingly, and introduced her two colleagues, the producers Rosemary Gill and Edward Barnes.

We chatted about what I'd done in my career to date, and whether I'd seen the show. I could honestly say that I had. Actually I had seen the very first episode way back in 1958, when it had been a short hobbies programme presented by Christopher Trace.

Anyway, after 15 minutes or so, they said thank you very much and I was ushered out. A few days later I was invited to attend the TV Centre again, this time for an audition. In due course, maybe a couple of weeks later, I was back at the BBC, only this time having been sent a script the previous day, of a 15-minute programme. The audition covered a number of the main elements that one may be required to deal with in a typical programme - talking straight to camera and giving some information; having a conversation with a co-presenter (I had gone weak at the knees meeting Val for the first time); demonstrating something (in this case a new kind of moped); and linking into and out of filmed inserts, with voice-over commentary. Pretty comprehensive, I'm sure you'll agree. I didn't have to bounce on the ubiquitous trampoline, but just about everything else was included.

We rehearsed in a fully crewed studio, and it was quite an awesome occasion. Finally we went for the take, and at first all went well, except for the fact that try as I might, the moped would not kick into life for me to ride in. So I pedalled it in, and delivered the script as if it had been working, and then continued the demo whilst apologising for its malfunction. But deep down I thought I had blown it.

The exact time-scale fails me, but I believe it was only two or three days later that the programme contacted me and asked me to go into the TV Centre again. This time it was for a short meeting with the trio of producers and again we had a short chat in the Blue Peter office. After which I was thanked for coming and I left the office. As I was about to enter the lift, Rosemary Gill came quickly out of the office and asked me to come back. They'd had a quick confab and decided I was the right man for the job, and I was offered it there and then. I can't tell you the euphoria I felt. Although it was not acting in the sense I knew it, it was performing, and after the months of disappointments and lack of confidence, it was just wonderful to feel that my talent was being recognised at last.

One might have thought I would get a much improved rate of pay but the BBC operated a system whereby you graduated from one level of payment to the next, slowly and simply. There were different categories of show, and children's TV was somewhere near the bottom of the list, and in any case it was less than half an hour long. I had got �30 a show for Doctor Who. I was rewarded here to the tune of �35 a programme for Blue Peter, with an extra �5 per day for any additional filming. But as there were two shows a week, I was much better off than the last time I had been in regular work. I discovered a few years later that they also worked on the principle that if you'd been on the show longest you got the most money. Consequently I was a fiver worse off than John, and a tenner worse off than Val. Later I would be a fiver better off than Lesley Judd! There would never be equality!

It was in November 1967 that I made my first appearance on the programme. One of the things I had discussed with Biddy and Edward was the fact that I was quite a good swimmer, having, amongst other things qualified as a Lifeguard whilst still at school with an Advanced Life-saving Certificate under my belt. So, for my introduction I went to Crystal Palace swimming baths and taught John and Valerie some basic life-saving skills in the diving pool and, at the end, we all looked into the camera and said “see you on Monday, goodbye”. I was, at last, a part of what has become, without doubt, the best and longest running children's TV programme in the world. It was a great feeling.

- Here's One I Wrote Earlier . . . is published by Green Umbrella Publishing at �18.99 hardback