The crack instantly attracted Liu Wuxie's attention. The crack was about three fingers in length and barely half an inch thick, similar to the size and thickness of a sword.1

The other stones might have similar cracks, but they differed from this one. This crack was manmade, while the other cracks looked natural.0

"Gu Yu, take your sword out!" A bold idea began to form in Liu Wuxie's mind. If this underground palace belonged to Gu Yu's ancestor, there was a high possibility that Gu Yu's longsword might be the key.1

Moreover, Gu Yu's longsword contained the Sky Dragon's will, which might bring surprises.1

After looking around and seeing everyone dispersed to search in the hall, Gu Yu handed his longsword over to Liu Wuxie, who inserted the sword into the crack. The sword perfectly fit the crack, leaving only the sword hilt outside.0

But seeing no commotion from the stone wall, Liu Wuxie wondered if he had made a mistake.0

After waiting for about half a minute, the dragon palace trembled, and cracking sounds began coming from the stone wall. The stone wall in front of Liu Wuxie suddenly split from the middle, and the ancient sword worked as a key, returning...0