"Of course not, what would I—"
"That's a lie." Rui stopped her right in her tracks.
His pitch-black eyes bore deep into hers.
"Don't try to pass blatant lies like that," Rui remarked. "I can discern them right away."
With his mind sense, he could detect pure fabrication on the spot. It became more complicated when the person he was speaking to relied on half-truths and misrepresentations to lie rather than to lie directly, so the method wasn't absolutely reliable by itself.