We have confused you with our other errors in this lesson. ghach is correct for "lurk/lie in wait". ghoch means "track down" and Qov suggested it for "stalk" (which ghach does NOT mean). Now your brain is on ghoch, but ghoch is not in this course. The sentences that were incorrectly using ghach have been removed and should disappear in a day or two. However, this sentence is correctly using ghach.
Ah, okay, this is very good to know. On a related note, thank you for suggesting https://hol.kag.org/ as a good first stop when I'm confused about a word. I'd looked up ghach at http://klingonska.org before making this post, and only found an entry for -ghach as a nominalizer suffix, but https://hol.kag.org/a/ghach makes the "lie in wait" definition very clear. And not to worry, I've internalized very few words to such an extent that this would cause lingering confusion -- on the contrary I think these will stick easily now. Thank you again!