Take bamboo, for example: Don’t be fooled by its beauty; it is invasive in nature. Left to its own devices, it will simply take over. Its roots will intermingle with the roots of other bamboo. It will form a network too strong to destroy.

Here is how you should plant it: carefully. Clump it together so it doesn’t have room to run. Make use of physical barriers—concrete, glass. Create an impenetrable wall.

5:30 – Wake your students with the Chinese national anthem. 6:00 – Morning exercises. 6:30 – Breakfast. 7:00 – Class. Make them sit straight as teachers march in and out of the classroom. At 21:00, allow them to hurry to their dormitories. Wash clothes and body before 21:30, when someone somewhere flips a switch and the power goes off in the entire building.

One afternoon, two lanky boys look quickly around the courtyard and then hoist themselves out of a dorm window. In one sleek movement, they clear the wall, leaping cleanly over the pieces of glass that jut from the top of the cement. Their feet smack loudly on the free ground. For a moment, they stand, sway tall and free. Then, they run.

Across the canal, some merchants point and whistle. They have seen the leap to freedom, and they have seen me watching.

The boys’ legs lengthen into sprints as they run the length of the canal. In their wake, laughter.