I like how you have the option_1 and option_2... however, since the options are the same, I'd recommend moving the rest of the method out into another method. could be (maybe?)

```ruby
def process_option(choice)
  @content = session[:book].current_page.content
  if session[:book].complete_game? 
    erb :conclusion
  else
    @option_1 = session[:book].current_page.options.first.preview
    @option_2 = session[:book].current_page.options.last.preview
    erb :adventure
  end
end
```

Also, you could do the following to only have one endpoint. The choice becomes a param.

```ruby
post '/options/:choice' do
  session[:book].input(params[:choice])
  # existing stuff
end
```