not only but also倒装整个句子疑问

Not only must I think of my fish all night，studying，without the object before me，what this unknown but most visible feature might be，but also，without reviewing my discoveries，I must give an exact account of them the next day.

what this unknown but most visible feature might be这里的might be如何放在最后面？

what this unknown but most visible feature might be是studying的宾语从句，studying+宾语从句，是must think of...的随着状语。

I know who he is. 假如你能理解这个简单的句子中的is为何放在了句末，你就应该能理解你的句子中为何might be放在句末了。