somnambulist

He must have promptly rejected an alternative explanation which would better fulfill the demands of verisimilitude (“My wife, poor thing, in her nervous condition, now is afflicted also with sleepwalking!”), seeing the laborious tasks to which the resumed somnambulist devotes herself: kneeling at the edge of a pit, she anoints the earth with murky philters (unless the implements she holds in her hand are to be interpreted actually as acetylene torches scattering sparks, to melt the lead seals of a coffin).