C137 Mysterious old man and luxurious book collection

"Hey, is that grandpa? I'm Xiao Xin, I want you to help me with something." Sun Yixin dialed the first number in the contact list and spoke sweetly to the other side.

"My Xiao Xin Xin, do you not plan to call me if there's nothing you need help with?" On the third floor of Wind and Yang Library, in a luxurious lounge, an ordinary dressed old man answered the phone.

"What