     func stop() {
         if let leader = leader {
             leader.close()
-            isFlowing = false
+            AuthenticationFlow.flow = nil
         }
     }
 

		if let raw = note.userInfo?["new"] as? Int, let state = AuthenticationState(rawValue: raw) {
			switch state {
			case .Authenticated:
				follower = alertSuccessWithTitle(NSLocalizedString("Logged In", comment: "Logged in alert title"),
				                                 andDetail: NSLocalizedString("Party Hearty!", comment: "Logged in alert detail"),
				                                 closeLabel: nil, dismissHandler: AuthenticationFlow.end(self))
				AuthenticationFlow.flow = nil
			case .Unauthenticated:
				follower = alertFailureWithTitle(NSLocalizedString("Not Logged In", comment: "Not logged in alert title"),
				                                 andDetail: NSLocalizedString("Better luck next time.", comment: "Not logged in alert detail"),
				                                 closeLabel: nil, dismissHandler: AuthenticationFlow.end(self) )
				AuthenticationFlow.flow = nil
			case .Transitioning:
				break
			}


	private let manager = AuthenticationManager.shared
	private var leader: SCLAlertViewResponder?
	private var completers = [AuthenticationFlowCompletion]()

    static var shared: AuthenticationFlow {
