A base under siege story featuring 5 and Nyssa, with an unremarkable alien threat and pacing. Nothing particularly surprising happens. However, the characterisation was pleasant; 4 out of the 5 human side characters had more than one dimension and the one who didn't was at least fun to hate. The sound design was also pretty vivid. I also enjoyed the inclusion of Silver Crow and how his Sioux background is important to the plot. Other stories would have villified the Whitlocks for bringing Silver Crow to England, but I thought it refreshing that in this story Silver Crow seems to have chosen to come himself and that he and the Whitlocks are on good terms.

A perfectly pleasant way to spend two hours, but not much more than that.