The tracking device in Zhang Heng's was fully optimized the moment it left the factory. Once the signal transmission had been blocked for more than eight hours, it would automatically trigger the meltdown process, causing irreversible damage to the user's cerebral cortex.
When Zhang Heng fought his enemies at the amusement park, he temporarily removed the signal blocking device because it was approaching the eight hours time limit. However, from the moment he laid down on the operating table, only five hours were left before the tracking device started to meltdown.
In order to ensure that Shengtang Morgan Group did not know Zhang Heng was still alive, Dr. Gu needed to complete the operation within five hours and extract the tracking device under Zhang Heng's cerebral cortex.
Even for Dr. Gu, who was known as one of the only two people in the new Shanghai 0297 who could perform this surgery, it was still a very challenging task for him.