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 |
| Sound | Peter Howell | Original Music Composer |
| Costume & Make-Up | Ann Arnold | Costume Design |
| Art | Nigel Jones | Production Design |
| Camera | Michael Williams | Camera Operator |
| Editing | Michael Lomas | Editor |
| Sound | Dave Brinicombe | Sound |
| Art | Bob Cosford | Graphic Designer |
| Costume & Make-Up | Susie Bancroft | Makeup Artist |
| Production | Yvonne Collins | Production Assistant |
| Production | Robert Gabriel | Production Manager |
| Writing | Eric Saward | Script Editor |
| Writing | Antony Root | Script Editor |
| Camera | Phil Wilson | Camera Operator |
| Crew | Dick Mills | Special Sound Effects |
| Lighting | Barry Hill | Lighting Director |
| Sound | David Hughes | Sound |
| Visual Effects | Nick Moore | Visual Effects |
| Editing | John Burkill | Editor |
| Visual Effects | Mat Irvine | Visual Effects Designer |
