Don’t panic, mate. The solution is in this image. The following video explains just the clues, then the theme is noted after that.

Unusually for me, there’s no nina, pangram or theme to this one. Well, a very slight ghost theme in that the four long across answers are all women’s names. But that’s it.

The title alludes to a fact referenced in Off-Grid episode #35, at 38 and a bit minutes in. Although the next fact mentioned could be my excuse for the mini-theme. Yeah, that’s it. Definitely what I planned. Genius, me.