The Chase is notable because Barbara and Ian end their travels with the Doctor. They had been with him since the very first adventure An Unearthly Child. He is angry and then sad to see them go. An interesting stylistic choice is made to depict their return to London, two years after they left, through a series of still photographs.
The extras on Disc 1 include commentary with Russell, O'Brien, Purves (who played two roles: Morton Dill and Steven Taylor), and director Richard Martin. "Cusick in Cardiff" (13 min) shows Dalek designer Raymond Cusick visiting the new series studios in 2008.
A second set of extras is packed. "The Thrill of the Chase" (10 min) is a making-of with director Martin. "Last Stop White City" (13 min) is about characters Barbara and Ian and the actors who portrayed them. "Daleks Conquer and Destroy" (23 min) presents the history one of the Doctor's greatest villains and oldest. "Daleks Beyond the Screen" (22 min) reveals the merchandising material related to the characters. "Shawcraft – The Original Monster Makers (17 min)" looks at prop house that worked on first three seasons of Doctor Who creating creatures. "Follow that Dalek" (12 min) is an extremely rare 8mm film shot around Shawcraft Models. There's not only a Dalek shown inside and out but the car from Chitty Chitty Bang Bang also can be seen. "Give-a-Show Slides (12 min)" was a children's product from the time that presents and this extras shows the images that would have appeared on the wall by way of a lighted projector. The standard "Photo Gallery" (5 min) and Info Text are also included.
Although grown-up Who fans may not enjoy these episodes because they are geared towards children, The Space Museum / The Chase are absolutely charming if the context can be appreciated.