Who sent a message to He Jun not to go to Fengwei sanatorium during the time-space call?

Alvin. He Jun suddenly remembered receiving a text message a few days ago, telling her not to go to Fengwei sanatorium. When Gu Mingzhe wanted to find Alvin's father, he saw him burning a ticket. He knew that Alvin had been in touch with his father. Alvin must be lurking in the Fengwei sanatorium, because the sanatorium is potentially dangerous. When He Jun and Gu Mingzhe arrived at the sanatorium, he already knew what would happen. The Call from Time and Space is a suspense criminal investigation drama produced by Penguin Film and Television, directed by Han, and starring Li and Du Chun.