The three of them went downstairs one after another, heading straight for the fifth-floor laboratory.

Pushing open the secondary bedroom door, Sun Ya and Wei De rushed in first to observe the mouse cage.

Su Jin, meanwhile, unplugged his slightly hot phone from the power bank.

Still tapping on his phone, Sun Ya's voice, tinged with fear, rang out: "Another one is missing! Mouse number six has disappeared... The cage is intact, no gaps."