"Hm." Shen Yuan purses his lips for a moment in thought before closing his fan and tucking it back into his sleeve. "Begging Lan-gongzi's pardon for asking a rather indelicate question, but has anyone injured him or otherwise caused him to spill blood since he arrived? Therein may lie the answer to this mystery." He clears his throat delicately. "If not, this one might conduct a simple test for Lan-gongzi, in order to determine his blood type. It would do him no lasting harm, but would require the use of a sharp knife or a needle."