Heartbeat - Season 7 - Eps 14: Substitute
Alf has to deal with a group of travellers who have a grudge against him. Alf is determined to catch them at whatever crime they're about to commit. He feels guilty for not convicting them of a crime they committed in the past during which one of his old colleagues was crippled. Alf spends time observing them and making notes, but unfortunately he is spotted and they take him and tie him up in a horse box. It is a race horse that they intend to steal, but during the process Alf makes his escape and drives off in the horse box. They follow him but road blocks have been set up and the thieves are caught. Greengrass lets some guides camp on his land but it proves more hassle than he bargained for.
About Heartbeat

Title: Heartbeat
First Air Date: 1992-04-10
Last Air Date: 2010-09-05
Status: Ended
Rating: 7/10 (from 31 votes)
Language: EN
Seasons: 19
Total Episodes: 372
Network: ITV1
Genres: Crime, Drama, Comedy
Production Companies: Yorkshire Television
Synopsis
Set during the 1960s in the fictional North Yorkshire village of Aidensfield, this enduringly popular series interweaves crime and medical storylines.
Cast

Derek Fowlds
Oscar Blaketon

William Simons
PC Alf Ventress

Tricia Penrose
Gina Bellamy

Peter Benson
Bernie Scripps

Gwen Taylor
Peggy Armstrong

Lisa Kay
Carol Cassidy

Joseph McFadden
PC Joe Mason

Nikki Sanderson
Dawn Bellamy

David Lonsdale
David Stockwell

Steven Blakeley
PC Geoff Younger