She sees Mr.Richards returning from one of those midnight walks, and falls down in a fit.

She says she has seen Master Harry's ghost--Master Harry being currently believed to be dead.
Shortly after, you see Mr.Richards on a like occasion, and you fall down in a fit.

You say you have seen the apparition of your husband, Henry Darling.

Putting all this together, and adding it up, what does it come to?
Are you good at figures ?" She could not answer him.

The ungovernable astonishment of hearing what she had heard, struck her speechless once more.
"Don't take the trouble to speak," said Doctor Frank, "my news has stunned you.