I just wrote a whole review for this, and then I realized what I didn't like about it.

This story has no well-constructed plot. It has worldbuilding, it has atmosphere, some admittedly great worldbuilding, it is a sequel to a 4th Doctor Adventure (as 8DAs tend to be), it sets up a mystery for the boxset, it has Daleks and two comedic characters, and thinks that is enough for the story to be a success.

It doesn't, in my opinion. First of all, most of the plot we follow Lucie, who explores the environment and gets caught in its nasty effects. In this, she is accompanied by a Briggs dynamic duo. (These are a homage to the 4th Doctor side character duos Briggs likes to have in most of his stories but which are never as good as the 4th Doctor side duos, as Briggs hasn't mastered balancing comedy and humanity enough to make them compelling.) The problem is that nothing much happens in this plot other than Lucie vaguely searching for the Doctor, and some of the dialogue is extremely clunky in its describing of the environment too.

On the side, there are Daleks, who receive the Doctor in the environment and ask him to save them. I think that's all they do. There is a bit at the end where Lucie has to choose to save them, but that decision has no relation whatsoever to the Daleks' actions in this play.

The Doctor meanwhile doesn't do anything. He has a box. We're supposed to care for this box because it was chucked into the black hole by the 4th Doctor, who again lends his shadow to loom over the 8DAs. I didn't care for the box.

Lots of decent to good components (the dynamic duo is not included in this), but the whole is lesser than its parts. Considerably so.