A Hooded Man!! That is the first clue!
"Did you ask him who it was, Martha?" Riku inquired, keeping his tone even.
"Oh, many times!" Martha exclaimed, a flash of her earlier frustration showing. "But he'd just brush it off, pat my hand, and say it was a 'secret mission' for Lord Gregor. Something very important and confidential, he said. He told me he couldn't tell me more, for my own safety and Pip's. He also started leaving for the manor at odd hours, sometimes long after his usual shift should have ended, saying there was extra work, special duties."
"A secret mission?" Riku exchanged a look with Lila and Elara. This was an expected excuse if he had to hide something.
"Did he seem afraid of this mission, Martha? Or perhaps excited by it?" Riku pushed further.
