Jim's not actually that much of a threat.
Right now, at least.
Serpent
John turned and recognized the young man, Jim, who'd been getting coffee just the day before. John recalled with uneasy clarity the excitement in Jim's voice at seeing Sherlock, nearly identical to his own- but there had been something off. John didn't know what it was, but it had set his senses on edge.
"Wonderful to see you again, John," Jim drawled, traces of the energetic yuppie transformed into something a little more urbane. If lime had been his color the other night, now he was serpent green.
"Hi," said John, a little uncomfortably.
"I need to ask you something."
Prompt was #7: lime