Relationships in different namespaces

I'm a little stuck on how relationships are defined between models in different namespaces. I have created this example to illustrate my problem and have added comments with my requirements.

class User < ActiveRecord::Base
  has_one :account # meaning Account
end

class Account < ActiveRecord::Base
  belongs_to :user # meaning User
  has_many :campaigns # meaning campaigns
  has_one :account # meaning SomeCollection::Account
end

class Campaign < ActiveRecord::Base
  belongs_to :account # meaning Account
end

class SomeCollection::Account < ActiveRecord::Base
  belongs_to :account # meaning Account
  has_many :campaigns # meaning SomeCollection::Campaign
end

class SomeCollection::Campaign < ActiveRecord::Base
  belongs_to :account # meaning SomeCollection::Account
end

The one I am most confused about is the relationship between Account and SomeCollection::Account. I would expect to access an instance of this as such -

account.some_collection_account
# => <SomeCollection::Account ...>