Love and fear were this: John, in a darkened swimming pool, wrapped in a heavy winter's coat of plastic explosives and sweat with a murderer's words in his mouth. “I will burn the heart out of you.” Bitter sense of loss. One last look. The first time.
Love and fear were this: John, with a gun pressed to the base of his skull. “On the count of three, shoot Doctor Watson.” All thought failing. All logic gone in a glint of blue steel. The pressure point he'd failed to see, twice, until the invisible thumb was digging in to raw nerve.
Love and fear. Have one, you have the other.
John walked the battlefield of Sherlock's life with stoic disregard. No, not right. With eagerness. It was what made him John, that essential, elemental thing that formed the pressure point at Sherlock's neck. It was what put him in danger. Both of them in danger.
Love and fear were this: John, standing on the pavement with a rifle aimed at his head. “I told you how this ends.” The dead hand on the pressure point relentless, digging with brutal efficiency into the one soft spot in Sherlock's armour. The ledge gritty beneath his shoes. John's voice on the phone, asking the impossible.
The third time, the pressure makes his knees buckle.