First off, compared to the average Who story The Visitation is very well made - the direction is good, the design work is fantastic (the only serial this designer worked on - did he overspend I wonder?) - the two main supporting guest stars - Richard Mace as the wonderfully over the top thespian highwayman and Michael Melia acting his socks off as the Tereleptil leader - are excellent, and the design of the Tereleptil leader's head, complete with animatronic lips and moving gills, is one of the best realised monster costumes in the series history. Where the story fails to come alive is the script. It's functional, and there are no gaping plot holes, but it's a very basic and formulaic story. Writer Eric Saward himself admits as much on the supplementary DVD extra material, explaining that he was working from memories of old Doctor Who TV stories he'd seen as a kid and was simply trying to replicate them. The Tereleptils are magnificently designed, but beyond being lizards there's nothing particularly interesting about them in the script - and if it comes to 'stranded aliens decide to take over the Earth' stories it's hard to see anybody choosing this above the likes of Terror of the Zygons (for example). Saward also struggles with the over-populated TARDIS - Tegan and Adric just about get enough things to do, but Nyssa gets pushed aside into a terribly basic and undramatic weapons building exercise that takes up nearly two episodes. Thank god for Richard Mace - while it becomes clear on the audio commentary that the regulars didn't think much of his performance he at least injects some life and comedy into an otherwise functional but dull story. On the extras front the audio commentary is the most entertaining, with Peter Davison, Sarah Sutton, Matthew Waterhouse & Janet Fielding typically taking the mickey out of the show and each other. Mini features on the director, author and incidental music composer are also typical of the care that the BBC lavish on even the most average of stories.