...and retreated quickly indoors. (Para. 7)
retreat: vi. move back, especially when forced; escape
The major decided to retreat because his men did not have enough arms to fight on. 少校决定撤退，因他没有足够的武器打下去。
They retreated from the flood to the top of a hill. 他们从洪水中撤退，退到一个小山顶上。
A brave man will not retreat from the real world. 勇敢的人不逃避现实。
indoors: ad. inside a building
Please take care that "indoor" is an adjective.
We play many sports indoors, but baseball is not an indoor sport. 许多运动项目是在室内进行的，但垒球不是一项室内运动。
They carried the benches indoors as it was raining outside. 外面下雨了，他们把凳子搬进屋里。