Strings and their evolutions as superstrings and M-theory have been one of the main focus of theoretical Physics for the last 40 years. In fact some have characterized superstrings and M-theory as the best candidates at explaining quantum gravity and providing a Theory of Everything. Others have claimed that it is “Physics of the next century provided for our exploration this century”. Yet not much has come out of it in terms of actual predictions or observation of anything about anything. In the context of explaining gravity with entanglement with multi-fold mechanisms, we encountered traces of superstrings and may have met some of them or their impacts. It qualifies for an alien encounter of the third type. Dualities between spacetime and superstrings were derived, yet nobody embarked or will ever embark on a superstring spacetime trip, at least. So no encounter of the fourth type. This paper summarizes what we have determined about strings, superstrings and M-theory as part of the multi-fold universe models. The observations and lessons learned are telling signs for superstring investigators.