Season 6 of the Companion Chronicles opens well as we have an example of a well written and structured piece that we did not always see throughout series 5. The story features four companions, but technically 6 actors to have played them. Steven Taylor, Zoe, Jo Grant and Romana I all have a narrative part, with Zoe a bit more interactive. The Vault is a UNIT one, and two UNIT personnel, previously unknown to us are introduced in the capacity of manning the vault/museum. Of course this is no ordinary museum and references are made to artefacts from the programme's past. The current curator and new starter are played by Eighth Doctor companion actors who cannot reprise their roles for contractual reasons. I feel this is an "awkward" choice because it draws attention to itself, and whilst the actors do a fine job, it still needed characters that are familiar in order to be true to the range.
The plot of introducing a newcomer to the museum and his inevitable curiosity landing them into a spot of bother is a good one, and the story is resolved by other clever items introduced along the way.
Overall Tales from the Vault is a worthy addition to the Companion Chronicle range, and could easily end up with sequels or a spin-off. The story feels a little lightweight because it is a story of small patchworks (historically set recordings from companions in the past) with a strong thread (the modern UNIT characters' dialogue and vault exploration). But for what it is trying to do, Big Finish have produced this very well. I prefer dialogue-heavy stories rather than ones that are almost entirely narrative, and this story is almost entirely dialogue, with the narration coming from four other different people.
In a range that takes more risks and is generally more inconsistent in quality than the monthly Big Finish 4 episode releases, Companion Chronicles have taken a lesser risk here in breaking the format. I want to give it 5 stars for ticking most boxes, but it lacks that something special we sometimes get to join the league of 5 star stories.