merlin’s secret being a visual thing. when he is around arthur or gwen or leon or morgana or [insert whatever character here] merlin seems pale and thin, almost like a ghost or an apparition. when the sun lands on him he reflects it like a corpse, he eyes seem dark and dull. he has this ethereal beauty to him, this otherworldly visage that leads many to believe he is of fae blood. he just doesn’t seem to be 100% human. but when he is ONLY with lancelot or gaius (cough or gwaine bc gwaine DEFINITELY knew) merlin is heartachingly human. merlin shines in the sunlight, colors are brighter and more vibrant around him, and his smiles are wide and his laughs are boisterous. he takes on color and leaves everyone wanting to know him. but when other join in or interact with the two, merlin shifts before their eyes so quickly and suddenly that they aren’t sure whether or not what they saw was a trick of the light. the idea still leaves them wanting more and wanting to see the merlin who is just so full of life but that merlin only appears for a small select group of people. merlin who has a guard so high that it has an effect of other’s perception of him.