The Overdose promotion would never be a good memory to any of them.
For Zitao, as for everyone else, the path had been very rough and painful and the fight to get everyone together after that had been hard. They had fought easily and misunderstandings had been many - but the arguments got them closer, got them to understand. 

For the Call me baby comeback they had to show a stronger side, show that they could still carry on the fame, be good enough even without the presence of Yifan and Luhan. The training had been draining, and many of them had gotten injured in the process. Zitao had hurt himself badly, and not being able to participate made him both sad and angry. When SM suggested him to go home to his family in China for a proper rest, Zitao was so happy he had started to cry. He loved being in Korea, but nothing could make him heal faster than his family. SM had given him the tickets, confirming with his parents when it was ok to come and when to return to Korea, and Zitao had left three days later. 

Being back in Qingdao was amazing and he'd been lying down in his favorite park, when he had heard it.
The laugh from the person he'd looked up to the most, the person he'd loved, the person who had once left