Sarah Jane Smith arrives at the home of her Aunt Lavinia in the cozy village of Moreton Harwood, only to find that Lavinia is nowhere to be found and that the Doctor has left her a parting gift in K·9 Mark III. With the help of K·9 and Lavinia's young ward Brendan Richards, Sarah Jane starts investigating her aunt's disappearance. In the process, they discover that Moreton Harwood is home to a coven worshipping the pagan god Hecate and preparing for a human sacrifice...
Unfortunately the movie K-9 and Company: A Girl's Best Friend is not yet available on HBO Max.
| Directing | John Black | Director |
| Writing | Terence Dudley | Writer |
| Production | John Nathan-Turner | Producer |
| Art | Nigel Jones | Production Design |
| Art | Bob Cosford | Graphic Designer |
| Writing | Eric Saward | Script Editor |
| Visual Effects | Nick Moore | Visual Effects |
| Sound | Peter Howell | Original Music Composer |
| Production | Robert Gabriel | Production Manager |
| Costume & Make-Up | Susie Bancroft | Makeup Artist |
| Editing | Michael Lomas | Editor |
| Writing | Antony Root | Script Editor |
| Camera | Phil Wilson | Camera Operator |
| Visual Effects | Mat Irvine | Visual Effects Designer |
| Sound | Dave Brinicombe | Sound |
| Lighting | Barry Hill | Lighting Director |
| Editing | John Burkill | Editor |
| Crew | Dick Mills | Special Sound Effects |
| Sound | David Hughes | Sound |
| Costume & Make-Up | Ann Arnold | Costume Design |
| Production | Yvonne Collins | Production Assistant |
| Sound | Ian Levine | Theme Song Performance |
| Camera | Michael Williams | Camera Operator |
