Shana recalled the words of the bald man when they parted: if there's work to be done, do it swiftly, don't hesitate or wait. Currently, Veteran Base has a moral obligation to fully support the Railway Bridge Base, but once the base is relocated, they'll be out of reach.
An interesting fact is that only a few people at Veteran Base are aware of the Railway Bridge Base possessing a helicopter.
...
To evade possible drone surveillance, Lin Wu, Maya, Xiaoji, Little Girl, Xiao Wu, and Little Knife left the base at four thirty in the morning the next day. Snow Egg, in addition to being responsible for command work, was researching electromagnetic interference equipment to counter drones.
Command work meant instructing the helicopter to hoist a small oil tank with a net rope.
