The Doctor plans to capture a dinosaur so he can discover who is transporting them through time. But Mike Yates is in league with the enemy and is ordered to stop the Doctor.

What is the recreational?

Starring Colin Baker
A two-part story by Philip Martin
On Varos the Doctor learns that video games aren't always fun.
CEEFAX SUBTITLES

1903. On the edge of Niagara Falls, something is wrong at Nikola Tesla's generator plant. The Doctor, Yaz, Ryan and Graham join forces with the inventor to save both him and planet Earth.

Roger Ashton-Griffiths is an English character actor, screenwriter and film director.

He  began his career as a singer with English National Opera at the London Coliseum.

He has appeared in numerous  films, including Terry Gilliam's The Brothers Grimm and Brazil, A Knight's Tale, Martin Scorsese's Gangs of New York, Roman Polanski's Pirates, Peter Greenaway's The Cook, the Thief, His Wife & Her Lover, Woody Allen's You Will Meet a Tall Dark Stranger and Olivier Dahan's Grace of Monaco.

Television roles include parts in Margaret, The Tudors,  Game of Thrones and Henry VIII: Mind of a Tyrant

Michael J. Jackson  is an English actor who appeared in the 1983 story The Kings Demons.

He appeared in several television series at the beginning of his career starting with one episode of Man About The House in 1973, followed by Anna Karenina, The Legend of Robin Hood, Play For Today, One Summer and Fairly Secret Army. 

In 1987 Jackson appeared in the popular and now cult television series Wish Me Luck.

Jackson also made several appearances in the television series Highlander: The Series in 1996-1997. he appeared in Now You See Her, The White Knight Stratagem, Dalziel and Pascoe and Judge John Deed.

In October 2010 he joined the cast of Emmerdale, playing the character Jerry Walsh.

Jackson's films include Sweeney 2, That Summer, The Glory Boys, Morons from Outer Space, The Fourth Protocol, There's Only One Jimmy Grimble, Family Portrait and Stepdad which also stars Ricky Tomlinson.

Mike Reid was born in Hackney, and made a career out of being a comedian and actor, most notably as Frank Butcher in Eastenders. He was also a presenter of the 1970s children's quiz show Runaround.

He had a small roles in some early Doctor Who stories including The Massacre of St Bartholomew's Eve .

Gary Downie was a production manager on many 1980's episodes of  Doctor Who, and partner the then producer John Nathan-Turner. 

His own analysis of the role of a production manager can be found on the BBC DVD release of The Two Doctors.

Downie also worked on I, Claudius, All Creatures Great and Small and Star Cops.

Downie was the author of the early eighties book 'The Doctor Who Cookbook'. Many Doctor Who celebrities donated recipes to the volume including Ian Marter and Lalla Ward.

Together with Nathan-Turner, Ian Fraser, and Fiona Hughes, he formed Teynham Productions, a theatrical group specializing in pantomime.

In Richard Marson's 2013 book The Life and Scandalous Times of John Nathan-Turner  Marson alleges Downie sexually assaulted him, and details other accusations of inappropriate behavior by Nathan-Turner and Downie, during the former's period as the series' producer.

Downie died on 19 January 2006 after a long battle with cancer. 

Max Adrian was an Irish stage, film and television actor and singer. He was a founding member of both the Royal Shakespeare Company and theNational Theatre.

In addition to his success as a character actor in classical drama, he was known for his work as a singer and comic actor in revue and musicals, and in one-man shows about George Bernard Shaw and Gilbert and Sullivan, and in cinema and television films, notably Ken Russell's Song of Summer. 

He also appeared in the Doctor Who story The Myth Makers as King Priam.