How does Lost Face develop the theme of Madness and Grief?

Lost Face by Jack London develops Madness and Grief across the chapters the companion marks for this theme.

Psychological breakdown from loss and isolation is a recurring motif, most poignantly in 'Flush of Gold,' where the woman's waiting for a dead man blurs into lunacy, and in the narrator's near-hysterical reactions to the dog Spot.

Marie Chauvet's descent into madness, living in isolation and haunted by the memory of a dead lover, illustrates the theme of grief overwhelming reason.