I+felt+that+I+must+scream+or+die!+and+now+--again!+--hark!+louder!+louder!++louder!+louder!

This passage shows his angery and fury.

[|hark](v) : to [|listen] [|attentively]; often used in the [|imperative] [|imperative](n) : the verbal [|mood] expressing an order (see [|jussive]). In English, the imperative form of a verb is the same form as that of its second person ("you") present tense; an essential action, a must: something which is imperative