Harriet was perceptive, Meesei had to credit her with that. She knew her room had been searched, which presented a problem for Meesei's original plan. If the vial was hers, then she likely knew that there was the possibility it could have been found. This meant that it was unlikely she would be able to catch her off-guard to produce a suspicious reaction. Harriet might have already seen through her original plan, but Meesei was not without any more tricks. She still had options, and now that she knew the room held its scents for a while, she had another avenue of investigation to pursue. 

"I did not search it, no." Meesei began, walking over towards the broken tile. There was no use going through the whole ruse of searching the rest of her room first; instead, she decided to go with her next best option. Kneeling down next to the tile, she lifted it up to reveal the hiding spot underneath. "But another did."

All that was inside the hole was a rag, atop which the vial had presumably rested before it was taken. Meesei had another trick, this time one much more subtle which a simple scent could not betray. As Meesei was examining the hiding spot, she rested her hand in such a way that, from Harriet's angle, it would block her view of where the vial had been resting. Meesei's posture looked perfectly normal and unremarkable, as if she was simply supporting her weight on her arm as she knelt down, and the fine details of what Harriet should be able to see from her angle could go unnoticed, especially if she already had response in mind before Meesei had even uncovered it. Beyond Harriet's reaction, there was also another thing Meesei was watching for, or rather, smelling for. A small, enclosed space like this hiding spot would hold scents even more easily than the rest of the room, such as the scents of those which had handled the vial. If the vial had been planted, Meesei would expect to find Gorlak's scent, along with an unfamiliar one, but if Harriet was indeed the traitor, then she would expect to find both Gorlak and Harriet's scent. 

"What is your explanation for this, Harriet?" Meesei asked. Her tone was accusatory, as being aggressive in her questioning might lead Harriet to defend herself in a way that would imply she had saw the vial.