I have seen the phrase "What hath alienators wrought" in the name of an article. Searching throught the web I learned that "hath" is the version of "has" in old English, but in the singular case (mostly used in the phrase "What hath God wrought", I guess it's biblical). Therefore, I am guessing that the phrase "What hath alienators wrought" is wrong and should be "What have alienators wrought".
Can someone tell me if I'm correct in my guessing or nor, and why? Thanks.