new_contents: #  --------
  # |C @ S aa|
  #  --------
  
  level.description("The wall behind you feels a bit further away in this room. And you hear more cries for help.")
  level.tip("You can walk backward by passing 'backward' as an argument to walk_. Same goes for feel, rescue_ and attack_. Archers have a limited attack distance.")
  level.clue("Walk backward if you are taking damage from afar and do not have enough health to attack. You may also want to consider walking backward until warrior.feel('backward').is_wall().")
  
  level.time_bonus(55)
  level.ace_score(105)
  level.size(8, 1)
  level.stairs(7, 0)
  
  level.warrior(2, 0, 'east')
  
  level.unit('captive', 0, 0, 'east')
  level.unit('thick_sludge', 4, 0, 'west')
  level.unit('archer', 6, 0, 'west')
  level.unit('archer', 7, 0, 'west')
  
subject: Add tower 6