Sherlock is the light and John is the conductor. Or so it’s been said.
The truth is more complex than that. (When is it not?)
Sherlock Holmes is brilliant like a man and brilliant like light, a sudden flare that no-one dares ignore. But what radiates from him is much too intense: unshielded, he burns. (And burns up.)
Light doesn’t need a conductor; light propagates through vacuum at nearly three hundred million metres per second. This is a constant of life, like body parts in the fridge and bullet holes in the wall.
As constant as John Watson.
Light is a wave. (Light is a particle.) Light refracts. (Light collides, like billiard balls.) Light is a contradiction that doesn’t bother to explain itself. (Because no explanation is necessary.)
Sherlock Holmes shifts, red and blue.
Light falls off like gravity, like electricity, inverse-squared; light emanates and decoheres; light interferes with itself (constructively) (destructively) and paints diffraction patterns in shadows. Light needs a focus.
John is a focus.
John reflects, like the smooth curve of a parabolic mirror. John redirects, like the twisting pathway of an optical fibre. (Total internal reflection.) John amplifies, like a seeded crystal. (And polarises. And modulates.)
Attenuation means loss; attenuation means dimming. John doesn’t intend to let that happen.
Sherlock may be luminous, but John makes him blaze.