Sentence:  He made love in a coach and six, and married in a coach and twelve, and all his horses were milk-white horses with one red spot on the back which he caused to be hidden by the harness. For, the spot "would" come there, though every horse was milk-white when Captain Murderer bought him. And the spot was young bride's blood. (To this <WSD>terrific</WSD> point I am indebted for my first personal experience of a shudder and cold beads on the forehead.) 
Meaning of the word marked with <WSD> tags:  Terrifying; causing terror.