I ended at:

rat he

I remove "h" but it doesn't accept "rate" as a correct word. Am I missing something?

In case anyone else finds this question before the other one, it was answered at https://news.ycombinator.com/item?id=44804178.

You need to remove a single letter while keeping the remaining letters in the same order - removing "h" from "rat he" leaves "rat e" not "rate".