background
bad
barb
barbed
barbwire
barrier
border
boundary
camp
cloud
confinement
containment
control
dark
denial
duress
dusk
enclosure
escape
evil
fence
forbidden
freedom
hedge
inclosure
iron
limit
obstacle
oppression
plug
point
prison
prisoner
sky
spike
spine
steel
stop
strand
suffer
sunset
twilight
war
wire