Laravel: Undefined offset in view index.blade.php

In my routes, I have this route defined as:

// app/routes.php
Route::resource('CharacterController');

      

        
        
        
      

    

Corresponding method in controller:

// app/controllers/CharacterController.php
public function index(){
    $characters = Character::all();
    $houses = House::all();

    return View::make('characters.index')->with(array('characters'=>$characters, 'houses' => $houses));
}

      

        
        
        
      

    

Finally, in the view:

// app/views/characters/index.blade.php
#this fires an error:
{{ $houses[$characters->house_id]->name }}

# at the same time this gives correct result: 
{{ $houses[1]->name }}

# and this IS equal to 1:
{{ $characters->house_id }}