The Beginning

Young people nowadays sleep late, especially in the "programmer's street" flats, where most of the programmers are from the nearby technology companies, and it is common for them to work overtime, or to stay up until 1 or 2 pm.

So you don't have to worry about getting bumped into by Xiao Heyun early in the morning.

You're not in uniform, you're in your regular clothes, rolled up and tucked into your backpack, looking like a regular programmer carrying a computer bag to work.

You feel your way into the flat with ease, wait for a while by the entrance door, follow the early morning residents into the building and take the lift up to the thirteenth floor.

You've got a better idea of what's going on here, having spent the last night in front of Xiao Heyun's house.

The one on the left is where Xiao Heyun lives. You have checked under the door mat and inside the electricity box, and there is no spare key, which means he lives alone and is too cautious and meticulous to leave any security risks to others.

But that doesn't mean there's nothing you can do to keep him from going out.

You take out the strong glue you have prepared and drip the glue through its thin opening along the doorway of the security door, filling a whole circle around the doorway of the security door, and dripping the glue into its keyhole, plugging it full of glue.

You figure that programmers don't get up too early, and if they do, it's before they leave the house.