Dinner?

'Let's meet.'

Si Ning turned over the letter to see there was nothing written on the other side of the paper. Even though he knew that was there to it yet he wondered if the real meaning of the two words might be in code because it could be Qiu Bai's way to avoid any attention to be directed at them since he might be aware of their last meeting being exposed to Xiu Zhicheng.

Si Ning decided to look deep into each letter after touching the paper and discovered it was just an ordinary paper yet he still tried to look carefully maybe there might be hidden words in the letters as he drew the letter closer to the candle and bent his head for a closer look but after reading it and considering each letter trying to form what code it might mean to form a meaningful sentence and cracking his brain thinking only to end up with nothing.

What sort of letter was this containing only two words, no location not even a time to meet.